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PubMedDate not supplied

Expression of glycine and the glycine transporter Glyt-1 in the developing rat retina.

Previous studies show that glycine transporter-1 (glyt-1) is a consistent membrane marker of adult retinal neurons that are likely to release glycine at their synaptic terminals (Pow, 1998; Vaney et al., 1998; Pow & Hendrickson, 1999). The current study investigated when glyt-1 immunoreactivity appeared in the postnatal rat retina, and whether all glycine-containing neurons also labelled for glyt-1. Ganglion cells, horizontal cells, and photoreceptors showed transient labelling. Many cells in the ganglion cell layer are immunoreactive for both glycine and glyt-1 at postnatal day (Pd) 1 but both are minimal by Pd5. Transient immunoreactivity for both glyt-1 and glycine was observed in presumptive horizontal cells between Pd5 and Pd10. At Pd1 many cells in the outer part of the retina which resembled immature photoreceptors were heavily labelled for glycine, but did not express glyt-1 these disappeared at older ages. These findings suggest diverse mechanisms and transient roles for glycine in the developing rat retina. In the adult rat retina, a subpopulation of amacrine cells are prominently immunoreactive for both glycine and glyt-1. These cells labelled for glycine at Pd1, but did not express significant levels of glyt-1 until Pd5. Processes from these amacrine cells did not reach the inner half of the inner plexiform layer until Pd10-14. Bipolar cells became glycine-IR between Pd10 and Pd14, but consistently lacked any glyt-1 immunoreactivity. This temporal pattern of labelling strongly indicates that bipolar cells label for glycine when gap junctions become functional between glycine/glyt-1 immunoreactive amacrine cells and cone bipolar cells.

Amino Acid Transport Systems, Neutral↗
PubMed2005

Development of a new sampling medium for bioaerosols.

OBJECTIVE: To develop a new sampling medium for detecting of bioaerosols. METHODS: The sampling media were tested by using Escherichia coli, Staphylococcus aureus and Serratia marcescens under static and active conditions, preliminary applications were performed using AGI-10 and high volume sampler. RESULTS: The average recovery rates were raised to 24.7%, 58.2%, 40.5%, 44.1%, 20.5%, and 15.4%, respectively in six consecutive experiments under static condition for 60 min at room temperature. Four kinds of sampling media were singled out after static experiments, which were referred to as "samplutions" PD1, PX2, TD1, and TX2, respectively. Under the active condition, the protective efficacy of PD1, PX2, TD1, and TX2 was 226% (153/47), 553% (111/17), 150% (120/48), and 268% (419/114), respectively. CONCLUSION: The samplutions have some effects on the subsequent nucleic acid detection, which could be avoided by employing standard nucleic acid extraction procedure. The newly developed samplution can be applied to the detection of bioaerosols.

Aerosols↗
PubMed2006

[Establishment and application of human papillomavirus type 16 pseudovirions neutralization assay].

Human papillomaviruses (HPV) are causally associated with cervical cancer and genital warts. Lack of permissive and productive cell cultures for HPV has hindered the study of HPV and evaluation of virus-neutralizing antibodies. So generation of infectious virions in vitro is highly desirable. In this report, we got high titer infectious HPV16 pseudovirions by calcium phosphate co-transfection of codon optimized HPV16 capsid genes L1 and L2 and reporter plasmids into 293FT cell line. Electron micrograph indicated that the pseudovirions were morphologically similar with the intact HPV16 virions. To evaluate the feasibility of using the pseudovirions to identify neutralizing monoclonal antibodies (mAbs), pseudovirions were incubated with 2-fold gradient dilution of the well identified mAbs V5, E70, U4 and D9 and then used to infect 293FT cells preplated in 96-well tissue culture plate. The infection of pseudovirions could be inhibited by neutralizing mAbs V5, E70 and U4 that recognize surface conformational epitopes on L1 VLP, but not by mAb D9 that is reactive to a linear epitope buried in VLP, which indicated that the pseudovirions could be used to evaluate the neutralization efficiency of mono- and polyclonal antibodies. The pseudovirions were then employed to identify neutralizing mAbs from 18 mAbs generated previously in our lab, 8 of which were conformational and 10 were linear. PD1 and 3D10, both of which recognized conformational epitopes on L1 VLP, had obviously strong neutralizing efficiency, with the neutralizing titer reached 81,920 and 20,480 respectively, while none of the linear mAbs were neutralizing, which reflected that rare linear mAbs have neutralization activity. The mechanism of PD1 and 3D10 block the infection of HPV16 pseudovirions need to be further studied. The technologies about generation of HPV16 pseudovirions and screening neutralizing mAb in our report are economical and efficient, can be easily used in large scale. They pave the way for rapid and precise evaluation of the protection efficiency of our prophylactic HPV vaccine being developed now.

Animals↗
PubMed1990

Expression of a class I MHC transgene: regulation by a tissue-specific negative regulatory DNA sequence element.

In vivo patterns of expression of a miniature swine class I major histocompatibility gene, PD7, were analyzed both in situ in the pig, and in transgenic mice. Structural analysis of PD7 DNA sequences revealed that PD7 is highly homologous to the pig gene PD1, which encodes a classical transplantation antigen. Despite the extensive homology, PD7 is expressed in situ at markedly lower levels than PD1 in nearly all tissues. Introduction of PD7 into mice results in a pattern of PD7 expression in the transgenic animals that parallels that observed in situ in the pig. Comparison of two lines of PD7 transgenic mice, which differ only in the extent of 5' flanking sequence, reveals the presence of a silencer element. The silencer activity is tissue specific: differences in PD7 expression are observed only in lymphoid tissues and skin. Skin from both lines of transgenics mediates graft rejection, but the rate of rejection correlates with the level of PD7 expression.

Amino Acid Sequence↗
PubMed1993

Aberrant biosynthesis and transport of class I major histocompatibility complex molecules in cells transformed with highly oncogenic human adenoviruses.

The expression of class I major histocompatibility complex antigens on the surface of cells transformed by adenovirus 12 (Ad12) is generally very low. The absence of class I antigens correlates with the high oncogenicity of this virus. In primary embryonal fibroblasts from transgenic mice that express both endogenous H-2 genes and a miniature swine class I gene (PD1), Ad12-mediated transformation results in complete suppression of cell surface expression of class I antigens, but only 50% of the cell lines tested demonstrated decreased steady state levels of class I mRNA. The complete absence of cell surface class I antigens is accompanied by decreased levels of newly synthesized class I molecules. Those molecules that are immunoprecipitated by class I-specific antibodies are assembled with beta 2-microglobulin, but their transport through the Golgi is inefficient. The biosynthesis of both the endogenous H-2K, H-2D, and the transgene product, PD1, is similarly altered in the transformed cells. The results suggest that Ad12 transformation is associated with both reduced synthesis rate and inefficient transport of class I molecules to the cell surface. This might be a general mechanism by which virus-infected or -transformed cells escape immune surveillance.

Adenoviruses, Human↗
PubMed1996

Delayed/salvage radiation therapy in patients with elevated prostate specific antigen levels after radical prostatectomy. A long term follow-up.

BACKGROUND: In this article the authors report an analysis and long term results of delayed/salvage radiation therapy administered to asymptomatic patients who had an elevated prostate specific antigen (PSA) level, many months to many years after radical prostatectomy. METHODS: During 1987 to 1990, 40 asymptomatic patients were found to have an elevated PSA level 9 to 96 months after radical prostatectomy. The patients underwent transrectal needle aspiration biopsy of the urethrovesicle junction anastomosis (uvj); 28 patients had a positive biopsy and 12 patients had a negative biopsy. Delayed/salvage radiation therapy was administered to the pelvis (45 Gray [Gy]) and prostate bed (59.5 Gy), including the uvj. RESULTS: Twenty-four of 37 patients (65%) were free of clinical disease. In 10 patients (27%), the radiation therapy resulted in a durable decrease in the elevated PSA level below a detectable level for a minimum 5-year follow-up. Five patients were alive with clinical disease. Eight died of disease. Three patients were lost to follow-up. CONCLUSIONS: This experience shows that delayed/salvage radiation therapy to the pelvis (45 Gy) and prostate bed (59.5 Gy), even many years after radical prostatectomy for pathologic stage pB, pC, and pD1 carcinoma of the prostate, was well tolerated and provided freedom from clinical disease in 24 of 37 patients (65%), and a decrease in elevated PSA level in 10 patients (27%). Delayed/salvage radiation therapy appears to be beneficial for patients who had undergone radical prostatectomy only and then developed rising PSA levels during the follow-up period.

Anastomosis, Surgical↗
PubMed1999

The relation of the MMPI-2 Pd Harris-Lingoes subscales to psychopathy, psychopathy facets, and antisocial behavior: implications for clinical practice.

Little is known concerning the correlates of the MMPI-2 Psychopathic deviate (Pd) Harris-Lingoes subscales. In four studies with undergraduates, Pd2 (Authority Problems) emerged as the most consistent marker of psychopathy and antisocial behavior and was the only Pd subscale to assess the callousness traditionally associated with psychopathy. Pd3 (Social Imperturbability) correlated highly with social potency and was the only Pd subscale to consistently assess low anxiety proneness. Pd1, Pd4, and Pd5 (Familial Discord, Social Alienation, and Self-Alienation, respectively) correlated highly with externalization of blame but exhibited few differential correlates. Pd2 exhibited statistically significant levels of incremental validity above and beyond all other Pd subscales in the prediction of global psychopathy and antisocial behavior. These findings indicate that several Pd subscales assess markedly different facets of psychopathy and suggest that consideration of different Pd subscale elevations may hold important implications for clinical practice and assessment.

Adolescent↗
PubMed2000

Thymosin-alpha1 regulates MHC class I expression in FRTL-5 cells at transcriptional level.

In this study we examined the effect of the synthetic peptide thymosin-alpha1 (T(alpha)1) on MHC class I expression in FRTL-5 cells. Treatment with T(alpha)1 increased expression of MHC class I surface molecules and mRNA, which reached its peak (153 +/- 8 % of the control value) after 12 h. Chloramphenicol acetyltransferase (CAT) analysis, following transfection with a plasmid containing the regulatory sequence of MHC class I (or its deletion derivatives) with the CAT reporter gene, and electrophoretic mobility shift assay experiments demonstrated that the action of T(alpha)1 was at the transcriptional level, and its mechanism of action is likely due to increased binding between the complex p50/fra-2 and the enhancer A sequence of the 5' flanking region of a swine class I gene (PD1). An increase in the expression of MHC class I surface molecules was also observed by flow cytometry in murine and human tumor cell lines and in primary cultures of human macrophages. This study shows for the first time an effect of Talpha1 on the regulation of gene expression at the molecular level, and may further contribute to explaining the results obtained using Talpha1 in the control of infectious diseases and tumor growth.

Animals↗
PubMed2006

A point mutation at the calreticulin gene core promoter conserved sequence in a case of schizophrenia.

Exposure to atypical antipsychotic drugs such as valproate increases the expression of chaperones that assist in the folding of proteins in the endoplasmic reticulum (ER) including calreticulin, GRP78/BiP, GRP94, and PD1. This neuroprotective role may be involved in the pathophysiology of neuropsychiatric disorders such as schizophrenia and bipolar disorder. The 5'-flanking region of the human calreticulin gene was screened in 100 cases of schizophrenia by PCR/SSCA between -485 and +1 basepair (bp) relative to the transcription start site. A G > C point mutation was detected at -48 in a case of paranoid schizophrenia, which was not detected in 280 unrelated control subjects (560 chromosomes). This is the first report of mutation in relation with the calreticulin gene. The -48G > C mutation creates a CpG site at the core promoter region of the gene. The role of this mutation remains to be clarified in the pathophysiology of the disease.

Adult↗
PubMed1995

Neurochemical effects of a 20 kHz magnetic field on the central nervous system in prenatally exposed mice.

C57/B1 mice were exposed during pregnancy (gestation days 0-19) to a 20 kHz magnetic field (MF). The asymmetric sawtooth-waveform magnetic field in the exposed racks had a flux density of 15 microT (peak to peak). After 19 days, the exposure was terminated, and the mice were housed individually under normal laboratory conditions. On postnatal day (PD) 1, PD21, and PD308, various neurochemical markers in the brains of the offspring were investigated and the brains weighed. No significant difference was found in the whole brain weight at PD1 or PD21 between exposed offspring and control animals. However, on PD308, a significant decrease in weight of the whole brain was detected in exposed animals. No significant differences were found in the weight of cortex, hippocampus, septum, or cerebellum on any of the sampling occasions, nor were any significant differences detected in protein-, DNA-level, nerve growth factor (NGF), acetylcholine esterase- (AChE), or 2',3'-cyclic nucleotide 3'-phosphodiesterase- (CNP; marker for oligodendrocytes) activities on PD21 in cerebellum. Cortex showed a more complex pattern of response to MF: MF treatment resulted in a decrease in DNA level and increases in the activities of CNP, AChE, and NGF protein. On PD308, the amount of DNA was significantly reduced in MF-treated cerebellum and CNP activity was still enhanced in MF-treated cortex compared to controls. Most of the effects of MF treatment during the embryonic period were similar to those induced by ionizing radiation but much weaker. However, the duration of the exposure required to elucidate the response of different markers to MF seems to be greater and effects appear later during development compared to responses to ionizing radiation.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1995

Effect of hypothyroidism induced by propylthiouracil and thiourea on male and female reproductive systems of neonatal mice.

The effect of hypothyroidism induced by 6-propyl-2-thiouracil (PTU) or thiourea (TU) on the development of the reproductive system in male and female neonatal ICR mice was investigated. PTU or TU was injected subcutaneously into experimental animals from postnatal day 1 (PD1) onward. The histological changes of the reproductive organs, formation of ovarian follicles, and spermatogenesis were examined on PD 14, 21, and 28, and the fertility of the hypothyroid mice in adulthood was followed. It was found that PTU or TU treatment did not produce an effect on the histology of the neonatal uterus and oviduct. In contrast, the drugs induced a decrease in the number of primordial follicles, multilaminar follicles, and Graafian follicles in the ovary. The number of follicles with degenerated follicular cells was increased. In the testis both PTU and TU treatments brought about a decrease in the number of seminiferous tubules with developing spermatids although the mean diameter of seminiferous tubules and the histology of the testis, epididymis, seminal vesicle, and coagulating gland was unaffected. The mating between hypothyroid females and euthyroid males and that between hypothyroid males and euthyroid females were normal with regard to the pregnancy rate, litter size, and sex ratio of offspring. The somatic growth of the resulting offspring was normal. It is concluded that the retarding effect on ovarian and testicular development in mice during neonatal period was not serious enough to adversely affect reproduction in the hypothyroid animals.

Animals↗
PubMed2004

NMDA and AMPA receptor expression and cortical neuronal death are associated with p38 in glutamate-induced excitotoxicity in vivo.

Early overstimulation of ionotropic glutamate receptors (iGluRs), such as the N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptors, produces excitotoxicity in several brain regions. The molecular composition of those receptors and their regulation by intracellular signaling systems could be determinants in the development of progressive neurodegenerative mechanisms in the central nervous system (CNS). Studies of p38 mitogen-activated protein kinase (MAPK) activation, morphologic changes including cell number, and the expression of the NR1 and GluR2 subunits, by reverse transcriptase-PCR were evaluated at early postnatal ages (postnatal day [PD]8-14) in cerebral cortex of rats treated with monosodium glutamate (MSG; 4 mg/g body weight) administered subcutaneously on PD1, 3, 5, and 7. An important increase in p38 activity at PD8 and loss of cortical cell number were observed from PD8-14 in animals treated with MSG, together with significant morphologic changes characterized by cell shrinkage, nuclear hyperchromatism, and cytoplasmic vacuolation. These morphologic changes were prevented by SB203580, an inhibitor of p38 signaling, at PD8-14. No change in cerebral cortex thickness was observed among experimental or control rats. A significant increase in NR1 subunit expression was observed in response to MSG from PD8-14. GluR2 expression increased from PD8-12, but at PD14, its expression was reduced to 54% with respect to controls. SB203580 prevented alone the decreased in GluR2 expression induced by MSG. These results suggest that initial neuronal death (at PD8 and 10) in cerebral cortex may be due to an excessive Ca2+ influx through NMDA receptors, whereas the further damage process could be mediated by AMPA receptors through p38 signaling. This could represent a determinant mechanism to decide whether nerve cells survive or die.

Activating Transcription Factor 2↗
PubMed1992

Long-term survival of mouse corpus callosum grafts in neonatal rat recipients, and the effect of host sensitization.

Previous studies have suggested that the incidence of spontaneous rejection among immunogenetically mismatched neural transplants in neonatal recipients varies significantly depending on the cellular composition of the graft material. For example, neuron-rich grafts of embryonic mouse retina generally survive for extended periods without showing signs of rejection after implantation into neonatal rats, whereas cortical xenografts, which contain abundant glial and endothelial cells as well as neurons, typically undergo rejection 4-6 weeks after implantation. To determine whether the presence of donor glia is responsible for this high incidence of spontaneous rejection, we examined the fate of a non-neuronal graft material composed predominantly of xenogeneic glial cells (post-natal day 3, PD3, CD-1 mouse corpus callosum) implanted into the mesencephalon of PD1 Sprague-Dawley rats. The distribution and survival of donor astrocytes were assessed using a monoclonal antibody specific for a mouse astrocyte surface antigen, M2. Thirteen of 16 animals sacrificed within 2 months of implantation had detectable transplants. In these animals, M2-positive cells frequently migrated well away from body of the graft, clustering in large numbers in several characteristic regions of the host brain. Unlike cortical grafts of similar age, the vast majority (93%) of callosal transplants showed no histological signs of rejection or major histocompatibility complex antigen expression in and around the transplant-derived cells. As previously noted in the neonatal retinal transplant paradigm, however, well-integrated 1-month-old corpus callosum grafts could be induced to reject by appropriate sensitization of the host immune system, implying that the host was not immunologically tolerant to the foreign neural graft. With longer survival times in unsensitized hosts, a progressively smaller percentage of animals had detectable donor astrocytes (5 of 10 animals at 3 months postimplantation and 4 of 16 animals at 4 months); in those 9 animals with surviving grafts, only small numbers of M2-positive cells were seen within the graft bed and surrounding host brain. However, only 2 of the 26 "long-term" animals showed evidence of graft rejection. These results indicate that mouse astrocytes show characteristic patterns of migration into the host brain when implanted into neonatal rats; however, these xenogeneic cells have a limited duration of survival. The infrequency with which even subtle signs of spontaneous rejection were detected in animals that had received corpus callosum xenografts suggests that an immune-mediated process is unlikely to be responsible for the time-dependent elimination of the donor astrocytes.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

Molecular engineering of microsomal P450 2a-4 to a stable, water-soluble enzyme.

Peptitergented P450 2a-4 (Pepti-P450), a water-soluble form of the mouse microsomal P450 2a-4, was genetically engineered and expressed in Escherichia coli. The NH2-terminal hydrophobic sequence (positions 2 to 19) of Pepti-P450 was replaced by a peptitergent PD1, amphipathic peptide consisting of 24 residues (C. E. Schafmeister, L. J. Miercke, and R. M. Stroud (1993) Science 262, 734-738). The expression level of Pepti-P450 (90,000 molecules/cell) was at least four times greater than that of wild-type P450 2a-4. Since Pepti-P450 was quite stable and was expressed as a peripheral membrane protein, it can be easily purified from the membrane fraction treated with Na2CO3 without using any detergents during the chromatographic steps. The purified Pepti-P450 retained the spectral and catalytic properties of the unmodified enzyme with a similar Km value for steroid 15 alpha-hydroxylase activity (19.7 microM in comparison to 14.2 microM of the wild-type). Gel permeation chromatography showed that the purified Pepti-P450 in the detergent-free buffer was an oligomer with an approximate molecular mass of 450 kDa. The replacement of the hydrophobic anchor domain with an amphipathic helix such as peptitergent, therefore, may provide a general method for engineering membrane-bound P450s to soluble enzymes.

Amino Acid Sequence↗
PubMed2001

Evidence for FSH-dependent upregulation of SPATA2 (spermatogenesis-associated protein 2).

Here we report the cloning and characterization of a novel cDNA named spata 2. SPATA2 is the ortholog of PD1, a human testicular protein which has been suggested to play a role in spermatogenesis. The spata 2 sequence reveals an open reading frame encoding a protein of 511 amino acids. Northern blot analysis with rat mRNA demonstrated two distinct transcripts of 2.2 and 4.0 kb. Tagging recombinant SPATA2 with the green fluorescent protein (GFP) and expressing the chimeric polypeptide in HLtat transfected cells indicated that SPATA2 is located in the nucleus. RT-PCR analysis revealed that spata 2 mRNA is expressed in the testis and to a lesser extent in the brain while skeletal muscle and kidney showed a barely visible signal. The same analysis demonstrated that isolated Sertoli cells express spata 2 mRNA. Treating Sertoli cells with FSH in vitro induced remarkable changes in the steady-state level of spata 2 mRNA in a time-dependent manner. In developing testis spata 2 transcripts were first detected 10 days post partum and expression levels increased steadily with age. The ability of FSH to stimulate spata 2 mRNA expression as well as its developmental expression suggests that this protein might play a role in regulating spermatogenesis and thus, according to the Gene Nomenclature Committee, we propose the name SPATA2 (Spermatogenesis associated protein 2) for this protein (or gene).

Amino Acid Sequence↗
PubMed1998

Localization of Six4/AREC3 in the developing mouse retina; implications in mammalian retinal development.

The Six4/AREC3 gene was originally isolated as a regulatory factor which bound to the positive regulatory region of the Na, K-ATPase alpha 1 subunit. It is a murine homologue of the Drosophila sine oculis (so) gene, which is essential for the development of the entire insect visual system. In this study, we attempted to determine the localization of the Six4/AREC3 gene product in the developing mouse retina in order to examine its role in retinal cell differentiation. Immunohistochemistry with anti-SIX4/AREC3 and anti-Na, K-ATPase alpha 1 subunit antisera was performed on developing mouse retinas, and immunoblotting analysis with anti-SIX4/AREC3 was also performed. The localization of Six4-like immunoreactivity (Six4-LI) showed a temporally regulated pattern: During embryonic development, Six4-LI was found in the nuclei of cells located at the inner neuroblastic layer of the retina as early as on ED12, nearly corresponding to the onset of retinal cell differentiation. In the PD1 retina, Six4-LI was observed in the nuclei of the ganglion cells, and increased its intensity until PD4, and thereafter kept its intensity until PD7 when Six4-LI was often found in the cytoplasm. On PD4, the presumptive amacrine cells found in the inner portion of the inner nuclear layer appeared to be immunostained in their nuclei. On PD7, the presumptive bipolar cells located in the outer portion were immunostained in the nuclei. After that, Six4-LI gradually decreased, and in the mature retina no detectable Six4-LI was observed in the nuclei. This pattern of Six4-LI localization during retinal development seemed to correlate with retinal cell differentiation, but did not correlate with the distribution pattern of Na, K-ATPase alpha 1 subunit protein-like immunoreactivity. These results suggest that the Six4 gene may play a role in the differentiation of neural retinal cells during mouse retinal development, rather than regulating the expression of the Na, K-ATPase alpha 1 subunit gene.

Animals↗
PubMed1993

Role of astroglial extracellular matrix in the formation of rat olfactory bulb glomeruli.

We describe the development of the olfactory bulb (OB) glomeruli, focusing on the role of purported astroglial-associated boundary molecules, as potential guidance factors in glomeruli formation. Glomeruli are unusual structures within the OB formed by extremely tight bundles of afferent fibers that fail to grow deeply into the brain. Using olfactory marker protein antibodies, we found that olfactory axons of stage E17-E18 rat embryos were organized into long strands at the outer-most edge of the bulb. By E20-E21 the axons clustered and formed small spheres and by PD1 they gathered into distinct glomeruli. Prior to and during the transformation of olfactory afferents into glomeruli, there was an enhanced expression of cytotactin/tenascin (CT) and chondroitin sulfate-containing proteoglycan (CS-PG) associated with VIM/GFAP-positive astroglial cell processes at the base of the glomeruli. During later stages of development (PD3-PD9), the GFAP-positive astroglial processes beneath and within the base of the glomeruli showed intensified GFAP staining while maintaining expression of CT and CS-PG. Some astroglial processes had extended and others went even further peripherally into the olfactory nerve layer (ONL) to encapsulate and fully infiltrate the glomeruli. By PD9, CS-PG and CT levels increased inside and outside the glomeruli. However, by PD15 both molecules had decreased inside the glomeruli but remained highly concentrated around the glomeruli to form rings. Thus, at later stages, axon/glia interactions which result in astroglial rearrangement and matrix alterations in relation to the glomeruli occur. Western blots of stage E20 bulb proteins revealed the presence of three proteoglycan core proteins each containing chondroitin-6-sulfate moieties. In addition, a type of keratan sulfate (KS) glycosaminoglycan was present in a core protein not associated with chondroitin-6-sulfate. Our data suggest that astroglial-associated ECM molecules CT and CS-PG, and perhaps KS-PG, present in the core of the early developing OB, could form a molecular "wall" that helps confine ingrowing olfactory axons within the ONL at the outer edge of the astroglial territory. We suggest that the astroglia do not precisely regulate the specific shape of the glomeruli, but rather play a fundamental role in directing the gross position at which formation of the synaptic glomeruli will occur.

Aging↗
PubMed1996

Carboxyl-terminal processing protease for the D1 precursor protein: cloning and sequencing of the spinach cDNA.

A previous study has demonstrated that the carboxyl-terminal (C-terminal) processing protease in spinach for the D1 precursor protein (pDl) of the photosystem II reaction center is a monomeric protein of about 45 kDa. Based on the amino acid sequence data of the purified protease, a cDNA clone encoding the enzyme has been identified and sequenced, from a spinach green leaf cDNA library. In order to determine the 5' end of the transcript, the rapid amplification of cDNA end (5'-RACE) technique was applied. By these analyses, the full-length transcript was established to consist of 1906 nucleotides and a poly(A) tail, containing an open reading frame (ORF) corresponding to a protein with 539 amino acid residues. By comparing the amino acid sequence of the purified protease with that deduced from nucleotide sequence of the cDNA clones, the enzyme was shown to be furnished with an extra amino-terminal extension characteristic of both a transit peptide and a signal sequence. This suggests that the protease is synthesized in the cytosol and translocated into the lumenal space of thylakoids. The mature part of the enzyme consists of 389 amino acid residues and exhibits a significant sequence homology with two groups of proteins as demonstrated by a computer homology search, i.e. (1) the deduced sequence of a protein proposed to be the C-terminal processing protease for pD1 in Synechocystis sp. PCC 6803, based on genetic experiments and (2) proteases for C-terminal cleavage identified in Escherichia coli and Bartonella bacilliformis.

Algal Proteins↗