Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Peripherins”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources

A novel component of the axonal cortical cytoskeleton, A60, defined by a monoclonal antibody.

A Mr 60,000 protein of the axonal cortical cytoplasm, which is recognized by a novel monoclonal antibody, is described. The antibody, DR1, was produced by immunizing mice with a soluble extract of bovine brain membranes that is enriched in known membrane cytoskeletal proteins. DR1 recognizes a Mr 60,000 protein in this extract. Immunofluorescence and subcellular fractionation reveal that the protein is primarily located in axons, where it appears to form a thick lining to the axolemma. Operationally, this Mr 60,000 protein is defined as a cytoskeleton-associated peripheral membrane protein. It is solubilized from brain membranes only under harsh conditions (0.1 M-NaOH), but not with KI (0.8 M) or Triton X-100 (1%). It is present at higher levels in the central nervous system than in peripheral nerves that have been examined. The Mr 60,000 protein copurifies with neurofilaments through cycles of assembly and disassembly. It does not appear to react with the anti-IFA antibody, suggesting that it is not a member of the intermediate filament class of proteins. This Mr 60,000 protein, which we designate A60, is distinct from other known neurofilament-associated proteins, including the Mr 60,000 protein alpha-internexin and the Mr 58,000 intermediate filament protein peripherin. A60 is suggested as being a previously unrecognized component of the axonal cortical cytoskeleton.

Animals↗

Somatic lamins in germinal vesicles of goldfish (Carassius auratus) vitellogenic oocytes.

In fish and amphibians, B-type lamins are divided into somatic (B1, B2) and oocyte-type (B3) lamins. In this study, we purified nuclear lamins from rainbow trout erythrocytes, raised an anti-lamin monoclonal antibody (L-200) that recognizes goldfish somatic-lamins, and isolated cDNAs encoding goldfish B-type lamins (B1 and B2) from a goldfish cell culture cDNA library. Goldfish B-type lamins are structurally similar to lamins found in other vertebrates with minor amino acid substitutions in the conserved region. Western blot analysis showed that goldfish oocytes contained mainly GV-lamin B3 as well as some somatic lamins. Laser-confocal microscope observations revealed that lamin B3 was present only in GV nuclear lamina, whereas somatic lamins were present in dense fibrillar structures throughout nuclear gels of isolated GVs. Similar nuclear filamentous structures were also observed in GVs of paraffin embedded oocytes. Epitope mapping indicated that L-200 recognized a conserved region containing a short stretch of the alpha-helix coiled-coil rod domain (Y(E/Q)(Q/E)LL). A similar motif is also present in other cytoplasmic intermediate filaments (i.e., vimentin, desmin, peripherin and GFAP). Taken together, these findings suggest that lamins or lamin-related intermediate filaments are an important component of the interior architecture of goldfish vitellogenic oocyte nuclei (GVs).

Amino Acid Sequence↗

Activity-dependent interaction of the intracellular domain of rat trkA with intermediate filament proteins, the beta-6 proteasomal subunit, Ras-GRF1, and the p162 subunit of eIF3.

Many responses to nerve growth factor (NGF) are regulated through the receptor tyrosine kinase trkA. To understand more fully the functions of trkA in NGF responsive cells, we have expressed the intracellular domain of rat trkA as a fusion protein with the yeast gal4 transcription factor, and used the fusion protein to probe rat and mouse cDNA libraries by the yeast two-hybrid system. We have identified a direct interaction between the intracellular domain of trkA and two members of the intermediate filament (IF) family of proteins, the guanine-nucleotide exchange protein Ras-GRF1, the p162 subunit of eIF3, and the beta-6 proteasome subunit. The interactions are dependent on an active trkA kinase, and RasGRF1, the beta-6 proteasomal subunit, and peripherin are directly phosphorylated by trkA. The interaction with trkA is not affected by mutations at either Tyr499 or Tyr794, the two major phosphotyrosine residues essential to the activation and receptor binding of Shc, FRS-2/SNT, and phospholipase Cgamma-1, and it is highly specific in vitro for trkA, with little or no binding observed with trkB and/or trkC. The results show that trkA may play a regulatory role in a variety of cellular functions in addition to neuritogenesis, including regulated protein degradation and transcriptional activation.

Amino Acid Sequence↗

Neurobehavioral characteristics of mice with modified intermediate filament genes.

Intermediate proteins comprise cytoskeletal elements that preserve the shape and structure of neurons. These proteins have been proposed to be involved in the onset and progression of amyotrophic lateral sclerosis (ALS), mainly characterized by motoneuron atrophy and paresis. In support of this hypothesis are the findings that genetically modified mice for intermediate filaments successfully mimic certain neuropathological aspects of ALS, such as reduced axonal caliber and retarded conduction speed in peripheral nerves, although often without leading to paresis. Nevertheless, even in those models with no overt phenotype, the involvement of intermediate proteins in motor function is underlined by the deficits in tests of balance and equilibrium revealed in mice containing transgenes for neurofilament of heavy molecular weight (NFH), alpha-internexin, peripherin, and vimentin. In addition, spatial learning was impaired in transgenic mice expressing transgenes for NFH and NFM, similar to the memory deficits reported in patients with ALS.

Amyotrophic Lateral Sclerosis↗

Desmin: molecular interactions and putative functions of the muscle intermediate filament protein.

Desmin is the intermediate filament (IF) protein occurring exclusively in muscle and endothelial cells. There are other IF proteins in muscle such as nestin, peripherin, and vimentin, besides the ubiquitous lamins, but they are not unique to muscle. Desmin was purified in 1977, the desmin gene was characterized in 1989, and knock-out animals were generated in 1996. Several isoforms have been described. Desmin IFs are present throughout smooth, cardiac and skeletal muscle cells, but can be more concentrated in some particular structures, such as dense bodies, around the nuclei, around the Z-line or in costameres. Desmin is up-regulated in muscle-derived cellular adaptations, including conductive fibers in the heart, electric organs, some myopathies, and experimental treatments with drugs that induce muscle degeneration, like phorbol esters. Many molecules have been reported to associate with desmin, such as other IF proteins (including members of the membrane dystroglycan complex), nebulin, the actin and tubulin binding protein plectin, the molecular motor dynein, the gene regulatory protein MyoD, DNA, the chaperone alphaB-crystallin, and proteases such as calpain and caspase. Desmin has an important medical role, since it is used as a marker of tumors' origin. More recently, several myopathies have been described, with accumulation of desmin deposits. Yet, after almost 30 years since its identification, the function of desmin is still unclear. Suggested functions include myofibrillogenesis, mechanical support for the muscle, mitochondrial localization, gene expression regulation, and intracellular signaling. This review focuses on the biochemical interactions of desmin, with a discussion of its putative functions.

Animals↗

Isolation of nonobese diabetic mouse T-cells that recognize novel autoantigens involved in the early events of diabetes.

Insulin-dependent diabetes mellitus (IDDM) is thought to result from chronic, cell-mediated, autoimmune islet damage. Our aim was to identify the earliest T-cell autoantigen in IDDM, reasoning that this antigen could be causally involved in the initiation of the disease. Identification of the earliest beta-cell-specific autoantigen is extremely important in allowing advances in prevention and treatment of initial events in the development of inflammatory insulitis that precedes beta-cell destruction and overt diabetes. Therefore, we analyzed the proliferative responses of peripheral T-cells from young, female nonobese diabetic (NOD) mice to extracts of pancreatic beta-cell lines. We were able to demonstrate that T-cells responsive to beta-cell antigens exist in the peripheral lymphoid tissue of these mice in the absence of deliberate priming before the manifestation of histologically detectable insulitis. T-cell lines and clones isolated from the peripheral lymphatic tissues of young, unimmunized, female NOD mice were also shown to react with extracts of beta-cells. Fractionation of the beta-cell extracts showed that these T-cell clones recognized multiple beta-cell-specific autoantigens but none of the previously reported putative autoantigens (glutamic acid decarboxylase [GAD]65, GAD67, Hsp65, insulin, ICA 69, carboxypeptidase-H, and peripherin). Thus, we can conclude that these responses are specific for novel beta-cell autoantigens. Finally, NOD T-cell proliferative responses were also seen to an extract of human islets suggesting potential shared antigenic determinants between human and mouse beta-cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Intermediate filament proteins during carcinogenesis and apoptosis (Review).

The intermediate filament network spreading from the cell periphery to the nucleus forms dynamic linkages between nuclear matrix, actin microfilaments, and the extracellular matrix. The six different types (types I-VI) of IF proteins consisting of nearly 50 different proteins form at least nine different kinds of filaments depending on the tissue types: keratins, lamins, vimentin, desmin, neurofilaments, peripherin, alpha-internexin, glial fibrillary acidic protein and nestin. Their tissue specific expression in normal cells and differential expression/assembly in neoplasia has been of immense value in tumor diagnosis. At the same time, recent in vitro studies point out that keratins, lamins and vimentin are subject to caspase-mediated proteolysis in an apoptosis-related manner. We reviewed the experimentally demonstrated P4-P1 motif specificities of caspases in the selection of substrates in the IF protein family. In addition, we provided clues to possible cleavage of additional IF proteins during programmed cell death, based on acceptable cut site motifs indicated by searches using the PIR protein sequence database. The present review concludes with presentation of evidence on the emerging roles of IFs in association with intermediate filament associated proteins in the dynamic remodeling of the cell during development of neoplastic phenotype and execution of apoptosis.

Amino Acid Sequence↗

Familial megacecum and colon in the rat: a new model of gastrointestinal neuromuscular dysfunction.

Gastrointestinal motility disorders are of considerable clinical importance in humans and animals. Abnormalities of smooth muscle and the enteric nervous system have been described. We have identified and characterized a new mutant stock of rats that develops severe megacecum and colon with pseudo-obstruction, Familial Megacecum and Colon (FMC). The inheritance pattern of FMC was characterized by selective breeding. Gastrointestinal motility was evaluated radiographically. Complete pathologic evaluations, including ultrastructural examination and staining of colonic segments for acetylcholinesterase, peripherin, vasoactive intestinal peptide, substance P, nitric oxide synthase, and somatostatin, were performed. Spontaneous contractility and contractile force in isolated colonic muscle strips were examined. Familial megacecum and colon is inherited as an autosomal recessive trait. The markedly dilated cecum and proximal portion of the colon are followed by a short, funnel-shaped segment and distal portion of the colon with normal or slightly reduced lumen. Although clinical features and gross anatomic changes of the colon resemble those of Hirschsprung's disease in humans and animals, aganglionosis is not a feature of FMC. An increase in somatostatin staining was observed in dilated regions of bowel. The spontaneous contractile frequency and contractile force were diminished in the affected colon. Familial megacecum and colon is a new mutant, distinct from previously described hereditary and targeted mutant rodent models that develop megacecum and colon as a result of distal colonic dysfunction. The functional or morphologic defect(s) that result in colonic dysfunction in rats with FMC was not determined. The disease may result from an absence or overexpression of a single or group of neurotransmitters or their respective neurons, receptor abnormalities, or defects in the intestinal pacemaker system.

Animals↗

Development of peripheral hindlimb and central spinal cord innervation by subpopulations of dorsal root ganglion cells in the embryonic rat.

The development of rat peripheral hindlimb and lumbar dorsal horn innervation by different subpopulations of dorsal root ganglion cells was investigated from embryonic day (E)13 to birth by using immunostaining. Antibodies to protein gene product (PGP) 9.5, growth associated protein (GAP) 43, and peripherin were used as pan-neuronal markers, RT97 for A fibres; calcitonin gene-related peptide (CGRP), trkA, and the lectin IB4 for small A and C fibres. Size frequency analysis showed that RT97 is a selective marker for large A cells at E18. Although both A and C fibres enter the hindlimb at E13-14, A fibres are the first to innervate the skin and dominate over small fibre innervation until later fetal life. CGRP expression in sensory axons appears at E19 and in all regions simultaneously, suggesting expression in existing fibres. All sensory terminals grow transiently to the skin surface before retracting subepidermally at late embryonic stages. The development of peripheral and central innervation by the same subpopulations of sensory neurons was compared. The entry of A fibre terminals into the lumbar dorsal horn at E14 coincided with hindlimb skin innervation. In contrast, C fibres were not detected in the dorsal horn until E18, 4 days after peripheral innervation. CGRP expression appears in both spinal cord and hindlimb targets at E19. IB4 binding in the central terminals began at E18 but was never observed in embryonic peripheral axons. These results demonstrate that in fetal skin, A fibre innervation dominates over C fibres. In addition, alathough peripheral and central innervation by A fibres coincide, this is not true for C fibres, suggesting that central target factors may control C fibre terminal growth within the dorsal horn.

Animals↗

Characterization of rhodopsin mis-sorting and constitutive activation in a transgenic rat model of retinitis pigmentosa.

PURPOSE: To determine the extent to which rhodopsin mis-sorting and constitutive activation of the phototransduction cascade contribute to retinal degeneration in a transgenic rat model of retinitis pigmentosa. METHODS: Retinas from transgenic rats expressing truncated rhodopsin (Ser334ter) were examined by light and electron microscopic immunocytochemistry at several time points. Retinal degeneration in transgenic rats raised in darkness was evaluated by quantification of outer nuclear layer thickness and by electroretinography. RESULTS: Mutant rhodopsin was found at inappropriately high levels in the plasma membrane and cytoplasm of Ser334ter rat photoreceptors. When the cell death rate was high this mis-sorting was severe, but mis-sorting attenuated greatly at later stages of degeneration, as the cell death rate decreased. The distributions of two other outer segment proteins (the cGMP-gated channel and peripherin) were examined and found to be sorted normally within the photoreceptors of these rats. Raising Ser334ter transgenic rats in darkness resulted in minimal rescue from retinal degeneration. CONCLUSIONS: Because dark rearing Ser334ter rats results in little rescue, it is concluded that constitutive activation of the phototransduction cascade does not contribute significantly to photoreceptor cell death in this rat model. The nature of the rhodopsin sorting defect and the correlation between the severity of mis-sorting and rate of cell death indicate that truncated rhodopsin may cause apoptosis by interfering with normal cellular machinery in the post-Golgi transport pathway or in the plasma membrane.

Animals↗

Loss of cone molecular markers in rhodopsin-mutant human retinas with retinitis pigmentosa.

PURPOSE: To examine the effect of rhodopsin mutations on cone photoreceptors in human retinas with retinitis pigmentosa (RP). METHODS: Four RP retinas with rhodopsin mutations and four normal retinas were examined by immunofluorescence with a battery of cell-specific antibodies against cone and rod cytoplasmic and outer segment membrane proteins. Areas of the retinas were studied that showed maximal preservation of photoreceptor structure. RESULTS: All four RP retinas showed loss of rods, ranging from mild (T-17-M), to more severe (P-23-H), to advanced degeneration (Q-64-ter and G-106-R). The majority of cones in the T-17-M and P-23-H retinas were cytologically normal but showed loss of immunoreactivity for the cytoplasmic proteins 7G6, calbindin, and X-arrestin. The cone outer segments (OS) remained positive for cone opsins and peripherin-2 (rds/peripherin). All remaining cones in the Q-64-ter and G-106-R retinas were degenerate, with short to absent OS, but had strong reactivity for these cytoplasmic and OS membrane markers. Cones in the maculas of the RP retinas were degenerate, with short to absent OS, but retained strong labeling for the cytoplasmic and OS proteins. CONCLUSIONS: Even before cones show cytologic changes in response to rod cell degeneration, they lose immunoreactivity for certain cytoplasmic proteins. These cones later show shortening and loss of OS, although their OS membrane proteins remain well labeled. Cones may down regulate expression of both cytoplasmic and outer segment membrane proteins in response to mutant rod cell dysfunction and/or cell death in human RP retinas. Such cytologic and immunocytochemical changes in the cones may presage death of these critical cells in the later stages of RP.

Aged↗

Loss of neurofilaments alters axonal growth dynamics.

The highly regulated expression of neurofilament (NF) proteins during axon outgrowth suggests that NFs are important for axon development, but their contribution to axon growth is unclear. Previous experiments in Xenopus laevis embryos demonstrated that antibody-induced disruption of NFs stunts axonal growth but left unresolved how the loss of NFs affects the dynamics of axon growth. In the current study, dissociated cultures were made from the spinal cords of embryos injected at the two-cell stage with an antibody to the middle molecular mass NF protein (NF-M), and time-lapse videomicroscopy was used to study early neurite outgrowth in descendants of both the injected and uninjected blastomeres. The injected antibody altered the growth dynamics primarily in long neurites (>85 microm). These neurites were initiated just as early and terminated growth no sooner than did normal ones. Rather, they spent relatively smaller fractions of time actively extending than normal. When growth occurred, it did so at the same velocity. In very young neurites, which have NFs made exclusively of peripherin, NFs were unaffected, but in the shaft of older neurites, which have NFs that contain NF-M, NFs were disrupted. Thus growth was affected only after NFs were disrupted. In contrast, the distributions of alpha-tubulin and mitochondria were unaffected; thus organelles were still transported into neurites. However, mitochondrial staining was brighter in descendants of injected blastomeres, suggesting a greater demand for energy. Together, these results suggest a model in which intra-axonal NFs facilitate elongation of long axons by making it more efficient.

Animals↗

Effect of immunosuppression on gene expression in the HSV-1 latently infected mouse trigeminal ganglion.

PURPOSE: To determine alterations in expression of genes in herpes simples virus (HSV)-1 latently infected mouse trigeminal ganglia (TGs), after treatment with cyclophosphamide and dexamethasone. METHODS: Scarified corneas of female BALB/c mice were inoculated with HSV-1 strain McKrae. Four weeks after inoculation, cyclophosphamide and dexamethasone were intravenously injected to induce HSV-1 reactivation. Uninfected mice were also treated with the immunosuppressants. Four groups of animals were studied: uninfected, not treated; uninfected, drug treated; latently infected, not treated; and latently infected, drug treated. PolyA+ mRNA from the TGs of each group was reverse transcribed, labeled with 32P, incubated on a 1185-gene array membrane, and analyzed by phosphorimaging. As a comparison and to confirm microarray results, semiquantitative RT-PCR was also performed for selected genes. RESULTS: The immunosuppressive drugs significantly increased expression of two genes (calpactin 1 light chain and guanine nucleotide-binding protein alpha-stimulating polypeptide [GNAS]) in the ganglia of uninfected mice compared with those in untreated uninfected mice. Ten genes were shown to be significantly increased in the latent TGs of mice treated with immunosuppressants compared with latently infected untreated mice. These genes were prostaglandin E2 receptor EP4 subtype (PTGER4), insulin promoter factor 1 (IPF1), glutathione S-transferase mu2, cyclin D2, peripherin, plasma glutathione peroxidase, methyl CpG-binding protein 2, retinal S-antigen, ErbB2 proto-oncogene, and GNAS. Eight genes were shown to be significantly decreased in the HSV-1 latent TGs treated with the drugs, compared with untreated latently infected mice. These genes were peripheral myelin protein 22, decorin, transcription factor AP-1, dystroglycan 1, myelin protein zero, mitogen-activated protein kinase 3, prothymosin beta 4, and brain lipid-binding protein. The results obtained by semiquantitative RT-PCR were similar to those obtained by microarray analysis. CONCLUSIONS: Those genes with expression altered by immunosuppressive drug treatment may play an important role in ocular HSV-1 recurrence. Changes in expression of genes in the prostaglandin pathway, a transcription factor, and an enzyme in the cell cycle are considered especially important in HSV-1 reactivation by immunosuppression and are reviewed.

Animals↗

Peptidergic nociceptors of both trigeminal and dorsal root ganglia express serotonin 1D receptors: implications for the selective antimigraine action of triptans.

Agonists at serotonin 1D (5-HT1D) receptors relieve migraine headache but are not clinically used as general analgesics. One possible explanation for this difference is that 5-HT1D receptors are preferentially expressed by cranial afferents of the trigeminal system. We compared the distribution of 5-HT1D receptor-immunoreactive (5-HT1D-IR) peripheral afferents within the trigeminal ganglion (TRG) and lumbar dorsal root ganglion (DRG) of the rat. We also examined the neurochemical identity of 5-HT1D-IR neurons with markers of primary afferent nociceptors, peripherin, isolectin B4, and substance P, and markers of myelinated afferents, N52 and SSEA3. We observed a striking similarity in the size, distribution, and neurochemical identity of 5-HT1D-IR neurons in TRG and lumbar DRG afferents. Furthermore, the vast majority of 5-HT1D-IR neurons are unmyelinated peptidergic afferents that distribute peripherally, including the dura, cornea, and the sciatic nerve. In the central projections of these afferents within the trigeminal nucleus caudalis and the spinal cord dorsal horn, 5-HT1D-IR fibers are concentrated in laminas I and outer II; a few axons penetrate to lamina V. At the ultrastructural level, 5-HT1D receptors in the spinal cord dorsal horn are localized exclusively within dense core vesicles of synaptic terminals. We observed scattered 5-HT1D-IR neurons in the nodose ganglia, and there was sparse terminal immunoreactivity in the solitary nucleus. The visceral efferents of the superior cervical ganglia did not contain 5-HT1D immunoreactivity. Our finding, that 5-HT1D receptors are distributed in nociceptors throughout the body, raises the possibility that triptans can regulate not only headache-associated pain but also nociceptive responses in extracranial tissues.

Animals↗

S-antigen localization in developing rds mouse retina.

The morphology of the photoreceptor cell and localization of the cytoplasmic soluble protein, S-antigen, in the retina of the developing retinal degeneration slow (rds) mutant mouse (2-505 postnatal days) were studied by improved immunocytochemical and freeze-substitution methods. Anti-S-antigen antibody labeling was observed first in the postnatal 10-day retina under light microscope. Labeling signals increased progressively to a maximum level in 20 days, and then decreased gradually to an undetectable level by 505 postnatal days. By electron microscopic immunocytochemical methods, S-antigen was detected first in the photoreceptor cells at 3 postnatal days, and increased with development. It was located in the entire cytoplasm of the photoreceptor cell including the rudimentary outer segment, but degenerated and disappeared by 505 postnatal days. S-antigen was also present in the membranous vesicles budding off from the photoreceptor membrane to the subretinal space. The rds photoreceptor cell seems to lose other soluble proteins together with these vesicles. From these results and other published data, we speculate that the degeneration of the photoreceptor cells may be the secondary effects of the loss of a large amount of soluble and membrane proteins following the malfunction of membrane. Recent reports show the rds mouse must have a gene defect in the membrane component such as peripherin or the 39 kDa protein.

Animals↗

Problems in fast intraoperative diagnosis in Hirschsprung's disease.

Histopathological evaluation of the proximal segment in colonic resections/biopsies for Hirschsprung's disease (HD) is very important because of the strong link between proximal segment histology and postoperative outcome. Therefore, we investigated whether a recently described rapid immunohistochemical staining technique using EnVision-antibody-complex is suitable for intraoperative diagnosis during surgery in HD. Various antibodies were applied on frozen sections from 20 colonic tissue samples including aganglionic segments, segments from the transitional zone, and normally innervated bowel segments to show ganglion cells (GCs) and cholinergic fibres. Several antibodies revealed positive staining of GCs (neurofilament, synaptophysin, peripherin, neural cell adhesion molecule/NCAM/CD56). However, none of these antibodies selectively identifies GCs. Microtubuli-associated protein 2/MAP2 stained few GCs only when incubation times were extensively prolonged. The antibodies applied to determine cholinergic innervation by immunohistochemistry (Acetylcholinesterase/AChE, cholinergic Acetyltransferase/chAT) failed. Rapid immunohistochemical technique using EnVision-antibody-complex on frozen sections of the large bowel is a) suitable for detection of many diverse antigens, including several neuronal antigens, b) not helpful to prove the presence or the absence of ganglion cells with any of the antibodies applied, c) not suitable to display the cholinergic innervation and iv) therefore is not helpful to shorten the consumption time during surgery in HD.

Acetylcholinesterase↗

[Prokaryotic expression of DnaJ-homologous chaperon PBP and preparation of rabbit antibody against PBP].

AIM: To express DnaJ-homologous chaperon peripherin-binding protein(PBP) gene in E.coli and prepare the rabbit antibody against PBP. METHODS: The PBP cDNA was amplified from the human fetal brain tissue by RT-PCR. After confirmed by DNA sequencing, the PBP-cDNA was cloned into expression vector pET28a and then the PBP gene was expressed in E.coli under the IPTG induction. The expressed protein was purified through Ni-NTA affinity chromatography column. The rabbit antibody against PBP was prepared by immunizing two New Zealand white rabbits using the purified PBP as immunogen. The titer and specificity of the antisera were determined by Western blot. RESULTS: The 720 bp PBP gene was amplified, cloned, and expressed in E.coli. The expressed product existed in the bacterial inclusion body and the supernatant of the bacteria lysate. The purified PBP reached electrophoretic purity. The rabbit antibody against PBP was prepared and its titer was about 1:1,600. Western blot analysis showed that the antibody could bind to the expressed PBP protein specifically. CONCLUSION: The PBP protein was expressed in E.coli and rabbit antibody against PBP was prepared successfully, which lays the foundation for further study on the structure and biological function of PBP.

Animals↗

Differential expression of N-myc in phenotypically distinct subclones of a human neuroblastoma cell line.

Neuroblastomas are malignant childhood neoplasms that arise from derivatives of the neural crest. We report the characterization of a new neuroblastoma cell line, designated NBL-W, derived from the primary tumor of a patient with stage IVS disease (S. L. Cohn, C. V. Herst, H. S. Maurer, and S. T. Rosen, J. Clin. Oncol., 5: 1441-1444, 1987) according to the criteria of Evans [A. E. Evans, G. J. D'Angio, and J. Randolf, Cancer (Phila.), 27: 374-378, 1971]. Neurite-bearing (N) and substrate-adherent (S) cell lines have been subcloned from the parent line. N and S cells can interconvert, and both cell types label with the neural crest cell surface marker antibody, HNK-1. Cells in the subcloned lines and in the parent line have been shown by Southern blot analysis to contain approximately 100 copies of the N-myc gene. Cytogenetic analysis shows a homogeneously staining region present on chromosome 19. Although these subclones are of identical genotype, the S cells express lower amounts of N-myc mRNA and protein as compared to the N cells. N cells express several neuronal proteins including the neurotransmitter-processing enzymes tyrosine hydroxylase and dopamine beta-hydroxylase, the neuronal intermediate filament proteins peripherin and NF66/alpha-internexin, and the neural cell adhesion molecule. S cells generally lack neuronal markers but express the mesenchymal intermediate filament protein vimentin, and a small subset of the S cells express glial fibrillary acidic protein. Some S cells were labeled weakly with neural cell adhesion molecule antibody; others were negative. S cells did not express the glial marker S-100 or a melanocyte marker, tyrosinase. Thus, S cells express the neural crest marker HNK-1 but do not express a set of antigens characteristic of any known cell type derived from the neural crest. These results are consistent with the suggestion that differential N-myc expression may be involved in the interconversion of N and S cells but indicate that the S cell phenotype need not represent a highly differentiated neural crest derivative.

Cell Differentiation↗