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PubMedDate not supplied

[Efficacy of SMC-electrophoresis of peat mud in primary chronic duodenitis].

Sinusoidal modulated current (SMC) electrophoresis of peat mud was used as monotherapy of primary chronic duodenitis in Uva sanatorium. A total of 65 patients with primary chronic duodenitis received SMC electrophoresis of peat mud diluted with distilled water. The effect was followed up with fibrogastroduodenoscopy and target biopsy of duodenal mucosa with further study of its morphological structure and element composition, acid-producing function of the stomach, hormonal profile, collagen metabolism. Positive changes were observed in clinical-endoscopic and morphological picture of the disease which is explained by favourable shifts in hormonal status and normalization of collagen metabolism in duodenal mucosa.

Adult↗
PubMed1990

[Clearance effect of 3H-cholesterol by Apo-AI/DPPC liposome from cultured SMC of rabbits and tree shrew].

Micellar liposomes were prepared by using Apo-AI from rabbit or tree shrew and dipalmitoylphosphatidyl choline (DPPC), with or without cholesterol through a rapid dialysis method. An obvious ability was noticed in clearing of 3H-cholesterol from the cultured smooth muscle cells (SMC) and a cross effect of Apo-AI originated from either rabbit's or tree shrew's serum on the clearance rate of 3H-cholesterol from the cultured SMC of these two species of animals was also obtained.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2005

Expression and localization of Muc4/sialomucin complex (SMC) in the adult and developing rat intestine: implications for Muc4/SMC function.

Muc4/sialomucin complex (SMC) is a high molecular mass heterodimeric membrane mucin, encoded by a single gene, and originally discovered in a highly metastatic ascites rat mammary adenocarcinoma. Subsequent studies have shown that it is a prominent component of many accessible and vulnerable epithelia, including the gastrointestinal tract. Immunoblot and immunofluorescence analyses demonstrated that Muc4/SMC expression in the rat small intestine increases from proximal to distal regions and is located predominantly in cells at the base of the crypts. These cells were postulated to be Paneth cells, based on their location, morphology, and secretory granule content. Immunohistochemistry indicated the presence of Muc4/SMC in these granules. Muc4/SMC expression was higher in the rat colon than small intestine and was abundantly present in colonic goblet cells, but not in goblet cells in the small intestine. Immunohistochemistry also suggested the presence of MUC4 in human colonic goblet cells. Biochemical analyses indicated that rat colonic Muc4/SMC is primarily the soluble form of the membrane mucin. Analyses of Muc4/SMC during development of the rat gastrointestinal tract showed its appearance at embryonic day 14 of the esophagus and at day 15 at the surface of the undifferentiated stratified epithelium at the gastroduodenal junction, then later at cell surfaces in the more distal regions of the differentiated epithelium of the small intestine, culminating in expression as an intracellular form in the crypts of the small intestine at about day 21. Limited expression in the colon was observed during development before birth at cell surfaces, with expression as an intracellular form in the goblet cells arising during the second week after birth. These results suggest that membrane mucin Muc4/SMC serves different functions during development of the intestine in the rat, but is primarily a secreted product in the adult animal.

Age Factors↗
PubMed1999

Isolation and characterization of a human cDNA homologous to the Xenopus laevis XCAP-C gene belonging to the structural maintenance of chromosomes (SMC) family.

We have isolated a human cDNA encoding a protein of 1288 amino acids that shows 77% identity in amino acid sequence to XCAP-C, Xenopus chromosome-associated polypeptide-C, belonging to the family of structural maintenance of chromosomes (SMC), which is known to play a crucial role in the proper condensation and segregation of mitotic chromosomes. In particular, an almost 200-amino-acid domain in the N-terminal, including an NTP-binding motif and that in the C-terminal domain, including a DA-box, were well conserved and showed 95% identity between human and frog, indicating that these two domains are functionally very important. The transcript of this gene was expressed ubiquitously in various human tissues, but thymus, testis, and colon seemed to express this gene more abundantly. We also determined its chromosomal location at 3q26.1 by fluorescence in situ hybridization.

Amino Acid Sequence↗
PubMed2006

Evidence that loading of cohesin onto chromosomes involves opening of its SMC hinge.

Cohesin is a multisubunit complex that mediates sister-chromatid cohesion. Its Smc1 and Smc3 subunits possess ABC-like ATPases at one end of 50 nm long coiled coils. At the other ends are pseudosymmetrical hinge domains that interact to create V-shaped Smc1/Smc3 heterodimers. N- and C-terminal domains within cohesin's kleisin subunit Scc1 bind to Smc3 and Smc1 ATPase heads respectively, thereby creating a huge tripartite ring. It has been suggested that cohesin associates with chromosomes by trapping DNA within its ring. Opening of the ring due to cleavage of Scc1 by separase destroys sister-chromatid cohesion and triggers anaphase. We show that cohesin's hinges are not merely dimerization domains. They are essential for cohesin's association with chromosomes, which is blocked by artificially holding hinge domains together but not by preventing Scc1's dissociation from SMC ATPase heads. Our results suggest that entry of DNA into cohesin's ring requires transient dissociation of Smc1 and Smc3 hinge domains.

Cell Cycle Proteins↗
PubMed2005

The role of SMC proteins in the responses to DNA damage.

The SMC proteins form the cores of three protein complexes in eukaryotes, cohesin, condensin and the Smc5-6 complex. Cohesin holds sister chromatids together after DNA replication and is involved in both the repair of double-strand breaks by homologous recombination and the intra-S-phase checkpoint. Condensin assists in the condensation of chromosomes at mitosis and also has a role in checkpoint control pathways. The Smc5-6 complex is involved in a variety of DNA repair and damage response pathways by as yet unknown mechanisms, but is also associated with repair by homologous recombination.

Chromosomal Proteins, Non-Histone↗
PubMed2004

An SMC-domain protein in fission yeast links telomeres to the meiotic centrosome.

Abnormal centrosomal structures similar to those occurring in human cancers are induced in fission yeast by overexpression of the pericentrin homolog Pcp1p. Analysis of abnormal Pcp1p-containing structures with quantitative mass spectrometry and isotope-coded affinity tags identified a coiled-coil, structural maintenance of chromosomes (SMC) domain protein. This protein, termed Ccq1p (coiled-coil protein quantitatively enriched), localizes with Taz1p to telomeres in normal vegetative cells. Fluorescence resonance energy transfer (FRET) measurements indicate that Ccq1p also interacts with centrosomal Pcp1p in mating pheromone-stimulated cells containing centrosomally clustered telomeres. We provide evidence that the Ccq1p-Pcp1p interaction, while essential for meiosis, is deleterious when forced to occur during vegetative growth. Cells lacking one ccq1 allele exhibit a loss-of-function phenotype including abnormally long cell length, chromosome segregation failure, telomeric shortening, and defective telomeric clustering during meiotic prophase. Our data indicate a mechanism underlying meiotic chromosomal bouquet formation and suggest a recruitment model for supernumerary centrosome toxicity.

Alleles↗
PubMed2005

SMC complexes in bacterial chromosome condensation and segregation.

Bacterial chromosomes segregate via a partition apparatus that employs a score of specialized proteins. The SMC complexes play a crucial role in the chromosome partitioning process by organizing bacterial chromosomes through their ATP-dependent chromatin-compacting activity. Recent progress in the composition of these complexes and elucidation of their structural and enzymatic properties has advanced our comprehension of chromosome condensation and segregation mechanics in bacteria.

Amino Acid Sequence↗
PubMed2003

Dissolution behavior of homologously generated surfactant molecular complexes (SMC) in aqueous media: A clue to the elucidation of the phenomenon "solubilization".

The solution behavior of homologously obtained crystalline surfactant molecular complexes (SMCs) that are generated between quaternary ammonium bromide and several additive materials has shed light on the recognition of fundamentals of solubilization. It has been revealed that the SMCs derived from long-alkyl-chain surfactants are sufficiently dissolved in water through the path of micellar dispersion above the cmc's of the complex surfactants, whereas the short-chain homologues cannot dissolve in water but dissociate the complexes, resulting in a heterogeneous phase made up of the liberated additives. The fact agrees perfectly with the familiar aspects of solubilization by surfactant; i.e., the longer the alkyl chain of the surfactant becomes, the more effective it is for solubilization. Based on these results, it has been deduced that the possibility for any pair of surfactant and solubilizate (additive) to realize solubilization simply depends on the relative importance of equilibrium of dissociation or association of the SMC species in aqueous medium.

Journal Article↗
PubMed1998

The SbcCD nuclease of Escherichia coli is a structural maintenance of chromosomes (SMC) family protein that cleaves hairpin DNA.

Hairpin structures can inhibit DNA replication and are intermediates in certain recombination reactions. We have shown that the purified SbcCD protein of Escherichia coli cleaves a DNA hairpin. This cleavage does not require the presence of a free (3' or 5') DNA end and generates products with 3'-hydroxyl and 5'-phosphate termini. Electron microscopy of SbcCD has revealed the "head-rod-tail" structure predicted for the SMC (structural maintenance of chromosomes) family of proteins, of which SbcC is a member. This work provides evidence consistent with the proposal that SbcCD cleaves hairpin structures that halt the progress of the replication fork, allowing homologous recombination to restore DNA replication.

Bacterial Proteins↗
PubMed2004

DNA interaction and dimerization of eukaryotic SMC hinge domains.

The eukaryotic SMC1/SMC3 heterodimer is essential for sister chromatid cohesion and acts in DNA repair and recombination. Dimerization depends on the central hinge domain present in all SMC proteins, which is flanked at each side by extended coiled-coil regions that terminate in specific globular domains. Here we report on DNA interactions of the eukaryotic, heterodimeric SMC1/SMC3 hinge regions, using the two known isoforms, SMC1alpha/SMC3 and the meiotic SMC1beta/SMC3. Both dimers bind DNA with a preference for double-stranded DNA and DNA rich in potential secondary structures. Both dimers form large protein-DNA networks and promote reannealing of complementary DNA strands. DNA binding but not dimerization depends on approximately 20 amino acids of transitional sequence into the coiled-coil region. Replacement of three highly conserved glycine residues, thought to be required for dimerization, in one of the two hinge domains still allows formation of a stable dimer, but if two hinge domains are mutated dimerization fails. Single-mutant dimers bind DNA, but hinge monomers do not. Together, we show that eukaryotic hinge dimerization does not require conserved glycines in both hinge domains, that only the transition into the coiled-coil region rather than the entire coiled-coil region is necessary for DNA binding, and that dimerization is required but not sufficient for DNA binding of the eukaryotic hinge heterodimer.

Amino Acids↗
PubMed2003

Hydrodynamics of pair-annihilating disclinations in SmC films.

The pair annihilation of smectic c-director defects with winding numbers +/-1 in a freestanding SmC film as a representative of the XY model is studied numerically, considering a full coupling of orientational degrees of freedom and hydrodynamics. A reduction of the annihilation time compared to the nonhydrodynamic treatment is observed. It is demonstrated that the +1 disclination moves considerably faster than the -1 one primarily due to hydrodynamic flow, weakly assisted also by elastic anisotropy. The stress tensor terms and material parameters relevant for this effect are identified.

Journal Article↗
PubMed1995

The rad18 gene of Schizosaccharomyces pombe defines a new subgroup of the SMC superfamily involved in DNA repair.

The rad18 mutant of Schizosaccharomyces pombe is very sensitive to killing by both UV and gamma radiation. We have cloned and sequenced the rad18 gene and isolated and sequenced its homolog from Saccharomyces cerevisiae, designated RHC18. The predicted Rad18 protein has all the structural properties characteristic of the SMC family of proteins, suggesting a motor function--the first implicated in DNA repair. Gene deletion shows that both rad18 and RHC18 are essential for proliferation. Genetic and biochemical analyses suggest that the product of the rad18 gene acts in a DNA repair pathway for removal of UV-induced DNA damage that is distinct from classical nucleotide excision repair. This second repair pathway involves the products of the rhp51 gene (the homolog of the RAD51 gene of S. cerevisiae) and the rad2 gene.

Amino Acid Sequence↗
PubMed1999

Hec1p, an evolutionarily conserved coiled-coil protein, modulates chromosome segregation through interaction with SMC proteins.

hsHec1p, a Homo sapiens coiled-coil-enriched protein, plays an important role in M-phase progression in mammalian cells. A Saccharomyces cerevisiae protein, identical to Tid3p/Ndc80p and here designated scHec1p, has similarities in structure and biological function to hsHec1p. Budding yeast cells deleted in the scHEC1/NDC80 allele are not viable, but this lethal phenotype can be rescued by hsHEC1 under control of the endogenous scHEC1 promoter. At the nonpermissive temperature, significant mitotic delay, chromosomal missegregation, and decreased viability were observed in yeast cells with temperature-sensitive (ts) alleles of hsHEC1. In the hshec1-113 ts mutant, we found a single-point mutation changing Trp395 to a stop codon, which resulted in the expression of a C-terminally truncated 45-kDa protein. The binding of this mutated protein, hshec1-113p, to five identified hsHec1p-associated proteins was unchanged, while its binding to human SMC1 protein and yeast Smc1p was ts. Hec1p also interacts with Smc2p, and the binding of the mutated hshec1-113p to Smc2p was not ts. Overexpression of either hsHEC1 or scHEC1 suppressed the lethal phenotype of smc1-2 and smc2-6 at nonpermissive temperatures, suggesting that the interactions between Hec1p and Smc1p and -2p are biologically significant. These results suggest that Hec1 proteins play a critical role in modulating chromosomal segregation, in part, through their interactions with SMC proteins.

Alleles↗
PubMed2005

Cellular growth under hydrostatic pressure using bovine aortic EC-SMC co-cultured ePTFE vascular graft.

High blood pressure (hypertension) is implicated in the development of atherosclerosis. Blood vessels are constantly subjected to stretch due to blood pressure and changes in stretch usually instigate adaptive vascular remodeling, including abnormal growth and proliferation of vascular smooth muscle cells (VSMCs) as well as extracellular matrix (ECM). In this experiment, we used bovine aortic endothelial cells and smooth muscle cells (EC-SMC) co-cultured ePTFE vascular grafts subjected to normal atmospheric pressure (as a control), and 100 mmHg hydrostatic pressure for 7 d. The increase of cell layer thickness was observed. When measured, the cell layer thickness increased by 116.2%. The increase of collagen (Type IV) synthesis was also observed in the immunohistochemistry assay. When stained with toluidine blue, the cells showed metachromatic phenomenon.

Animals↗
PubMed1985

Establishment and characterization of human malignant pleural mesothelioma cell line SMC-1.

A cell line (SMC-1) has been established from the resected tissue of a patient with malignant pleural mesothelioma which has been pathologically confirmed to be the mixed type. The cell line is characterized by the pleomorphy and multilayered growth of the cells with the population-doubling time of approximately 32 h, the highest mitotic index of 46--50% and the modal chromosome number of 69-70. Transplantation of the cells into the animals can produce tumors bearing histological resemblance to the original material. The cultured cells, xenografted tumor cells and the cells from the host specimen show similar histochemical expressions. These data meet the requirements of a human malignant pleural mesothelioma cell line. The establishment of this cell line will serve as a useful tool in clinical research of diagnosis and treatment of this devastating disease.

Adult↗
PubMed1985

Cell kinetics of growth cartilage in spondylo-metaphyseal chondrodysplasia (smc) mice.

The gene for spondylo-metaphyseal chondrodysplasia (smc) in the mouse disrupts the formation of growth plate cartilage. No cartilage columns are found in the head of the tibia and secondary centres of ossification appear very late. The number of cells labelled with tritiated thymidine is sharply reduced at 16, 18 and 21 days of age but hypertrophic cell height is normal. Cells taking up label are found scattered throughout the large cartilaginous epiphyses.

Animals↗
PubMed1984

The ultrastructure of mandibular condylar and rib cartilage from mice carrying the spondylo-metaphyseal chondrodysplasia (smc) gene.

The ultrastructural appearance of cartilage from a new mutant spondylo-metaphyseal chondrodysplasia (smc) is described. The matrix is abnormally rich in collagen fibres which often form a sheath around the chondrocytes. Collagen balls - spherical inclusions of collagen fibres - are a unique and characteristic feature of the matrix, and the chondrocytes contain large amounts of lipid.

Achondroplasia↗