Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The 67-kDa laminin receptor (67LR) is a nonintegrin cell surface receptor that mediates high-affinity interactions between cells and laminin. Overexpression of this protein in tumor cells has been related to tumor invasion and metastasis. Thus far, only a full-length gene encoding a 37-kDa precursor protein (37LRP) has been isolated. The finding that the cDNA for the 37LRP is virtually identical to a cDNA encoding the ribosomal protein p40 has suggested that 37LRP is actually a component of the translational machinery, with no laminin-binding activity. On the other hand, a peptide of 20 amino acids deduced from the sequence of 37LR/p40 was shown to exhibit high laminin-binding activity. The evolutionary relationship between 23 sequences of 37LRP/p40 proteins was analyzed. This phylogenetic analysis indicated that all of the protein sequences derive from orthologous genes and that the 37LRP is indeed a ribosomal protein that acquired the novel function of laminin receptor during evolution. The evolutionary analysis of the sequence identified as the laminin-binding site in the human protein suggested that the acquisition of the laminin-binding capability is linked to the palindromic sequence LMWWML, which appeared during evolution concomitantly with laminin.
Mol Biol Evol 1998 Aug
PMID:The 67-kDa laminin receptor originated from a ribosomal protein that acquired a dual function during evolution. 971 29

CD44, the predominant vertebrate cell surface receptor for hyaluronan, exists in a variety of isoforms resulting from alternative splicing of a single gene. Particular spliced variants of CD44 correlate with increased cell motility, and with poor clinical prognosis in several kinds of carcinomas. Combinations of 9 variant exons that confer this enhanced motility on tumor cells are inserted into a single site in the middle of the extracellular domain of CD44. Evidence suggests that phosphorylation of 2 serine residues in the intracellular domain of CD44 are involved in controlling these events. However, evidence is lacking as to the nature of such kinases. Acidic amino acids in close proximity to these 2 serine residues suggests casein kinase II (CKII) is involved. We now show an antisense phosphorothioate oligonucleotide designed to hybridize to the AUG translation initiation codon of subunit CKII alpha' mRNA blocks in vivo phosphorylation of CD44 in MDA231 breast tumor cells, and at the protein level decreases ectopic expression of total CD44 as well as the metastatic v-7 CD44 isoform. Furthermore subplateau RT-PCR analysis demonstrated antisense transfected MDA231 tumor cells had significant down-regulated or eliminated mRNA transcripts of metastatic CD44 isoforms. CKII as a CD44-associated serine kinase therefore may serve as an important molecule in a signaling cascade that produces a variety of cellular responses in MDA231 breast cancer cells. Since the 3'-untranslated region of CD44 mRNA contain 4 dispersed AUUUA sequences which serve as signals targeting mRNA for rapid turnover, a mechanism is proposed by which CD44 phosphorylation mediates labile message stabilization, hence providing insights into the processes involved in cancer cell growth, invasion and metastasis.
Mol Cell Biochem 1998 Oct
PMID:Phosphorylation stabilizes alternatively spliced CD44 mRNA transcripts in breast cancer cells: inhibition by antisense complementary to casein kinase II mRNA. 978 39

Gp180, a duck protein that was proposed to be a cell surface receptor for duck hepatitis B virus, is the homolog of metallocarboxypeptidase D, a mammalian protein thought to function in the trans-Golgi network (TGN) in the processing of proteins that transit the secretory pathway. Both gp180 and mammalian metallocarboxypeptidase D are type I integral membrane proteins that contain a 58-residue cytosolic C-terminal tail that is highly conserved between duck and rat. To investigate the regions of the gp180 tail involved with TGN retention and intracellular trafficking, gp180 and various deletion and point mutations were expressed in the AtT-20 mouse pituitary corticotroph cell line. Full length gp180 is enriched in the TGN and also cycles to the cell surface. Truncation of the C-terminal 56 residues of the cytosolic tail eliminates the enrichment in the TGN and the retrieval from the cell surface. Truncation of 12-43 residues of the tail reduced retention in the TGN and greatly accelerated the turnover of the protein. In contrast, deletion of the C-terminal 45 residues, which truncates a potential YxxL-like sequence (FxxL), reduced the protein turnover and caused accumulation of the protein on the cell surface. A point mutation of the FxxL sequence to AxxL slowed internalization, showing that this element is important for retrieval from the cell surface. Mutation of a pair of casein kinase II sites within an acidic cluster showed that they are also important for trafficking. The present study demonstrates that multiple sequence elements within the cytoplasmic tail of gp180 participate in TGN localization.
Mol Biol Cell 1999 Jan
PMID:Sequences within the cytoplasmic domain of gp180/carboxypeptidase D mediate localization to the trans-Golgi network. 988 Mar 25

Cell-to-cell signals between T lymphocytes and antigen-presenting cells strictly regulate the development of the immune response. It has clearly emerged that among these signals few cell surface receptor-ligand pairs, such as CD40 and its ligand, CD154, are mandatory for the induction of lymphocyte activation. The early observation that mutations of CD154 gene are responsible for a human severe immunodeficiency primed an impressive number of studies aimed to functionally characterize this receptorial system in view of therapeutically exploiting its properties. Indeed, various approaches aimed to disrupt natural CD40-CD154 interaction were highly effective in the prevention and treatment of several experimental models of autoimmune disease and transplant rejection. In parallel, abnormalities of this pathway were constantly found in several immunologically-mediated human diseases. Furthermore, a number of studies have dissected the role of CD40 and its ligand in the immune response against various microbial and viral pathogens. Since these molecules are often expressed by tumor cells, it is not surprising that great efforts have been made to address their function also in the development of cancer. Most recent data strongly suggest an involvement of endothelial CD40 in the vascular processes that lead to atherogenesis. This review focuses on the most significant advances in the understanding of the molecular regulatory events involving CD40 and its ligand in experimental and human disease.
Int J Mol Med 1999 Apr
PMID:CD40-CD154 interaction in experimental and human disease (review). 1008 5

The cell surface receptor Notch is required during Drosophila embryogenesis for production of epidermal precursor cells. The secreted factor Wingless is required for specifying different types of cells during differentiation of tissues from these epidermal precursor cells. The results reported here show that the full-length Notch and a form of Notch truncated in the amino terminus associate with Wingless in S2 cells and in embryos. In S2 cells, Wingless and the two different forms of Notch regulate expression of Dfrizzled 2, a receptor of Wg; hairy, a negative regulator of achaete expression; shaggy, a negative regulator of engrailed expression; and patched, a negative regulator of wingless expression. Analyses of expression of the same genes in mutant N embryos indicate that the pattern of gene regulations observed in vitro reflects regulations in vivo. These results suggest that the strong genetic interactions observed between Notch and wingless genes during development of Drosophila is at least partly due to regulation of expression of cuticle patterning genes by Wingless and the two forms of Notch.
Mol Cell Biol 1999 Aug
PMID:Notch and wingless regulate expression of cuticle patterning genes. 1040 62

Epidermal growth factor (EGF) and heparin-binding EGF-like growth factor (HB-EGF) exert their activities through the same cell surface receptor. In the present study, the role of EGF in cell kinetics of rat gastric epithelial cell line, RGM-1, in which HB-EGF is known to function in an autocrine fashion, was investigated. EGF stimulated the mucus glycoprotein synthesis which is characterized with cell maturation, but competed with HB-EGF for cell proliferation. By flow cytometric analysis, EGF inhibited G2/M transition by 48 h after stimulation and induced apoptosis manifested by hypodiploid DNA by 72 h after stimulation. Consistent with this, DNA ladder formation together with the histone-associated DNA fragments was found in EGF-treated cells. These results indicate that EGF and HB-EGF possess different functions in RGM-1 cells and that EGF acts as a mediator of both cell maturation and apoptosis in these cells.
Int J Mol Med 1999 Sep
PMID:Epidermal growth factor-mediated cell maturation and apoptosis in RGM-1 rat gastric mucosal cells. 1042 74

Background: CD44, a major cell surface receptor for hyaluronic acid, is a family of ubiquitous cell surface glycoproteins. Altered levels of CD44 expression, seen in many epithelial neoplasms, have prognostic implications. Expression of standard and variant isoforms of CD44 was assessed in normal and neoplastic human prostate tissue and culture cells to evaluate as a marker for malignant transformation. Methods and Results: Expression of CD44s, CD44R, v5, v6, v7/8 and v10 was assessed in prostate tissue (benign and malignant) and cell lines (DU-145, PC-3, LNCaP, p69) and primary cultures of normal prostates and adenocarcinoma cells obtained from prostatectomies using reverse transcriptor polymerase chain reaction, Western blotting, and immunofluorescence. No CD44 expression was seen in LNCaP cells. p69, DU-145, and PC-3 cells expressed CD44s and CD44R. p69, cells demonstrated a 1000-bp-long form of CD44 mRNA, unique to this normal cell line. Both normal and neoplastic prostatic tissue demonstrated CD44s on Western blotting. Conclusions: In agreement with previous studies, prostatic adenocarcinoma cells, except LNCaP, expressed CD44s. Different patterns of CD44 expression were seen in benign and neoplastic prostate. Benign prostate exhibited higher v5 protein levels, whereas neoplastic prostates demonstrated higher CD44s expression. CD44s expression was identified in all neoplastic prostates as compared with only 50% of the benign prostates. No significant difference in expression of the other variants assessed (v6, v7, v7/8, and v10) was observed in the benign and neoplastic prostates.
Mol Diagn 1997 Sep
PMID:CD44 Expression in Benign and Neoplastic Human Prostates. 1046 10

Scant information is available to date on the intracellular trafficking of the TSH receptor. In the present study we have used stably transfected L cells that express the TSH receptor, 225I-labeled TSH, and antireceptor antibodies as well as gold-conjugated antireceptor monoclonal antibodies and hormone. The latter allowed us to study, by electron microscopy, the cellular distribution and endocytosis of TSH receptor. The receptor was initially localized on the plasmalemma proper and in clathrin-coated pits but was excluded from smooth vesicles open to the cell surface. It was internalized through clathrin-coated vesicles. Constitutive endocytosis represented 10% of cell surface receptor molecules. Endocytosis was increased 3-fold by incubation with hormone. The majority of internalized receptor molecules (90%) was recycled to the cell surface, whereas the hormone was degraded in lysosomes. This recycling of receptor was inhibited by administration of monensin. Electron microscopic and confocal microscopic studies were repeated in primary cultures of human thyroid cells and showed a distribution, and endocytosis pathways, very similar to those observed in transfected L cells. A previous study has shown the LH receptor to be endocytosed in high proportion and to be degraded in lysosomes. Confocal microscopy and colocalization studies with transferrin receptor confirmed that the highly homologous LH and TSH receptors exhibit, when expressed in the same cells, very different cellular trafficking properties. The use of LH/TSH receptor chimeras showed that transmembrane-intracellular domains contain information orienting the protein toward recycling or degradative pathways. The extracellular domain seems to play a role in the extent of intemalization. These observations should now allow the identification of the molecular signals involved.
Mol Endocrinol 1999 Oct
PMID:Internalization and recycling pathways of the thyrotropin receptor. 1051 76

The receptor for advanced glycation end products (RAGE) has been proposed as a cell surface receptor that binds amyloid-beta protein (Abeta), thereby triggering its cytotoxic effects [S.D. Yan, X. Chen, J. Fu, M. Chen, H. Zhu, A. Roher, T. Slattery, L. Zhao, M. Nagashima, J. Morser, A. Migheli, P. Nawroth, D. Stern, A.M. Schmidt, RAGE and amyloid-beta peptide neurotoxicity in Alzheimer's disease, Nature 382 (1996) 685-691.]. A cDNA library of human lung was screened for RAGE with an appropriate hybridization probe. In addition to cell surface RAGE, one clone was found which encodes a new version of RAGE, termed hRAGEsec, which lacks the 19 amino acids of the membrane-spanning region and is therefore secreted. Comparison with the genomic sequence revealed that the synthesis of the secreted isoform requires alternative splicing. The deduced protein sequence of the mature hRAGEsec consists of 321 amino acids with a predicted molecular mass of 35.66 kDa. The pattern of expression of hRAGEsec in human brain was analyzed by in situ hybridization histochemistry. The most intense expression of the gene in contrast to cell surface RAGE was detected in hippocampal CA3 pyramidal cells, dentate gyrus granule cells, cortical neurons as well as glial cells in white matter. To investigate the interaction between Abeta and RAGE and another scavenger receptor, SRA, under physiological conditions, they were co-expressed with human betaAPP(695)-SFAD in a human cell and the level of Abeta in the condition medium was assessed by immunoprecipitation and enzyme-linked immunosorbent assay (ELISA) analysis. A nearly 100% reduction of Abeta from the conditioned medium of hRAGE cells and approximately 40% reduction from the SRA-cells implied that hRAGE could be a prominent cell surface receptor interacting with Abeta.
Brain Res Mol Brain Res 1999 Aug 25
PMID:cDNA cloning of a novel secreted isoform of the human receptor for advanced glycation end products and characterization of cells co-expressing cell-surface scavenger receptors and Swedish mutant amyloid precursor protein. 1052 70

Laminin G-like (LG) modules in the extracellular matrix glycoproteins laminin, perlecan, and agrin mediate the binding to heparin and the cell surface receptor alpha-dystroglycan (alpha-DG). These interactions are crucial to basement membrane assembly, as well as muscle and nerve cell function. The crystal structure of the laminin alpha 2 chain LG5 module reveals a 14-stranded beta sandwich. A calcium ion is bound to one edge of the sandwich by conserved acidic residues and is surrounded by residues implicated in heparin and alpha-DG binding. A calcium-coordinated sulfate ion is suggested to mimic the binding of anionic oligosaccharides. The structure demonstrates a conserved function of the LG module in calcium-dependent lectin-like alpha-DG binding.
Mol Cell 1999 Nov
PMID:The crystal structure of a laminin G-like module reveals the molecular basis of alpha-dystroglycan binding to laminins, perlecan, and agrin. 1061 25


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>