Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Quantitative immunoblotting of prostate cancer patient sera revealed that most prostate specific antigen was in complexes with alpha 1-antichymotrypsin or alpha 2-macroglobulin with little of it being free antigen. Complexes of prostate specific antigen with these protease inhibitors in patient sera comigrated during electrophoresis with the respective purified complexes. Each complex was selectively removed from patient sera by absorption with specific antibodies. When prostate specific antigen was added to normal plasma, complexes with alpha 2-macroglobulin appeared first and after 1 hr, the distribution was approximately 40% free antigen, approximately 40% complexes with alpha 2-macroglobulin, and approximately 20% complexes with alpha 1-antichymotrypsin. These data show that prostate specific antigen reacts more readily with alpha 2-macroglobulin than with any other
protease inhibitor
in plasma and that the antigen complexes with alpha 2-macroglobulin in vivo in cancer patients.
Biochem
Mol
Biol Int 1995 Nov
PMID:Prostate specific antigen-alpha 2-macroglobulin complexes in prostate cancer patient sera. 862 98
Decidualization-associated protein (DAP), the quantitatively major secretory product of the mesometrial decidua in the rat, is a pl variant of the liver-derived acute-phase reactant, alpha-2-macroglobulin (alpha 2M). Alpha 2M, a broad spectrum
protease inhibitor
, has been demonstrated in the human to bind a variety of cytokines and growth factors. In humans, the quantitatively major secretory product of decidual tissue is an insulin-like growth factor (IGF) binding protein. In this study, we have therefore tested the ability of liver- and decidual-derived alpha 2M in the rat to bind IGF-I. Alpha 2M purified from acute-phase plasma and DAP purified from cytosolic extracts of decidual tissue and medium from tissue incubations both bound radiolabeled IGF-I. The binding of IGF-I was principally dependent upon the coincubation of the protein with a proteinase. Therefore, it occurred during the conversion of the "slow" to the "fast" form of alpha 2M. Pretreatment with proteinase to produce the fast form before addition of the IGF-I reduced the binding. Binding was enhanced at a ratio protein:proteinase of 1:1. Results from gel electrophoretic analysis were consistent with the covalent linkage of IGF-I to alpha 2M during the cleavage of the "bait region." A saturable displacement by increasing concentrations of unlabeled IGF-I suggested high affinity interaction. Under conditions of demonstrated binding to purified proteins binding in acute-phase plasma, decidual tissue extracts and tissue incubation medium were associated with a high molecular weight species which was confirmed to represent alpha 2M and DAP, respectively. Our studies demonstrate that IGF-I may now be added to the list of regulatory peptides which alpha 2M may bind and that, in rat decidua, DAP may represent the functional homolog of decidual IGFBP-1 in the human and regulate growth factor function during placental development.
Mol
Reprod Dev 1996 May
PMID:Major secretory product of the mesometrial decidua in the rat, a variant of alpha-2-macroglobulin, binds insulin-like growth factor I via a protease-dependent mechanism. 872 98
As observed for neurons in situ, phosphorylated neurofilament (NF) epitopes are normally segregated within the axonal cytoskeleton of NB2a/d1 cells. However, accumulations of phosphorylated NFs develop in NB2a/d1 perikarya following exposure to aluminum salts and following inhibition of proteolysis. In the present study, we observed that perikarya of cells exposed to both aluminum and the
protease inhibitor
C1 (also known as "AllNal") were more intensely labeled by monoclonal antibodies directed against both nonphosphorylated and phosphorylated epitopes than were cells treated with either aluminum or
protease inhibitor
alone. Since these monoclonal antibodies crossreact with tau, we also immunostained cells treated under these conditions with monoclonal antibodies directed against phosphate-insensitive (5E2) and phosphorylated (PHF-1) epitopes of tau. Aluminum treatment, but not C1 treatment, induced accumulation of total tau isoforms as judged by an increase in 5E2 immunoreactivity. Neither treatment, either separately or in combination, induced an increase in PHF-1 immunoreactivity. These findings suggest that alterations in immunoreactivity with SMI antibodies reflected increases in NF epitopes. This was confirmed by immunoblot analyses. Since proteolysis is apparently instrumental in maintaining the normal distribution patterns of phosphorylated NF epitopes, these findings implicate deficiencies in proteolytic mechanisms in the development of neurofibrillary pathology, and underscore the possibility of a multiple etiology in human neuropathological conditions.
Mol
Chem Neuropathol 1995 Dec
PMID:Inhibition of proteolysis enhances aluminum-induced perikaryal neurofilament accumulation but does not enhance tau accumulation. 874 24
Treatment of WEHI 231 immature B-lymphoma cells with an antibody against their surface immunoglobulin (anti-Ig) induces apoptosis and has been studied extensively as a model of B-cell tolerance. Anti-Ig treatment of exponentially growing WEHI 231 cells results in an early transient increase in c-myc expression that is followed by a decline to below basal levels; this decrease in c-myc expression immediately precedes the induction of cell death. Here we have modulated NF-kappaB/Rel factor activity, which regulates the rate of c-myc gene transcription, to determine whether the increase or decrease in c-Myc-levels mediates apoptosis in WEHI 231 cells. Addition of the serine/threonine
protease inhibitor
N-tosyl-L-phenylalanine chloromethyl ketone (TPCK), which blocks the normally rapid turnover of the specific inhibitor of NF-kappaB/Rel IkappaBalpha in these cells, caused a drop in Rel-related factor binding. TPCK treatment resulted in decreased c-myc expression, preventing the usual increase seen following anti-Ig treatment. Whereas inhibition of the induction of c-myc expression mediated by anti-Ig failed to block apoptosis, reduction of c-myc expression in exponentially growing WEHI 231 cells induced apoptosis even in the absence of anti-Ig treatment. In WEHI 231 clones ectopically expressing c-Myc, apoptosis induced by treatment with TPCK or anti-Ig was significantly diminished and cells continued to proliferate. Furthermore, apoptosis of WEHI 231 cells ensued following enhanced expression of Mad1, which has been found to reduce functional c-Myc levels. These results indicate that the decline in c-myc expression resulting from the drop in NF-kappaB/Rel binding leads to activation of apoptosis of WEHI 231 B cells.
Mol
Cell Biol 1996 Sep
PMID:Inhibition of c-myc expression induces apoptosis of WEHI 231 murine B cells. 875 60
The low density lipoprotein receptor-related protein (LRP) is a multifunctional cell surface receptor that binds to the
protease inhibitor
alpha 2-macroglobulin (alpha 2 M). LRP has also been identified as the apolipoprotein E (apoE) receptor that mediates lipid metabolism. Recently it has been reported that apoE4, one of three common isoforms of apoE, is a main risk factor of Alzheimer's disease (AD). Moreover, all three of these proteins are reported to accumulate in the senile plaques in the brains of Alzheimer's patients. To understand the roles of LRP in the normal development of the central nervous system (CNS) and in the pathogenesis of AD, we studied the developmental expression and localization of LRP mRNA in the CNS. We used Northern blot analysis to investigate the developmental profile of LRP mRNA in the rat brain. LRP mRNA was first detected as early as in 18-day-old embryonic rat brain and was continuously expressed thereafter. A particularly high level of expression of the mRNA was observed in the perinatal stage. We also determined the cellular distribution of LRP mRNA in the CNS of 20-day-old embryonic and 6-week-old adult rat brains by in situ hybridization using a digoxigenin-labeled antisense riboprobe to LRP mRNA. In the embryonic rat brain, LRP mRNA was highly expressed in most of the cells, mainly neurons and glial cells. In the adult rat, LRP mRNA was expressed mostly in neurons in both the brain and the spinal cord. These results suggest that LRP plays crucial roles in development of the brain.
Brain Res
Mol
Brain Res 1995 Oct
PMID:Expression and distribution of low density lipoprotein receptor-related protein mRNA in the rat central nervous system. 877 44
A locust within chromosome XIII of Saccharomyces cerevisiae containing four genes upregulated by osmotic stress has been characterized. Two of the genes, but not their osmotic induction, were already described: the DNA damage-inducible gene DDR48 and the
protease inhibitor
gene PAI3. The two novel genes encode a cytoplasmic aldehyde dehydrogenase (ALD2) and a peptide of unknown function (SIP18). These genes form a cluster of two pairs of divergent promoters regulated by osmotic stress. The regulation of the divergent ALD2 and DDR48 genes, however, occurs by different mechanisms. ALD2 exhibits maximum induction with 0.3 M NaCl, negative regulation by protein kinase A and dependence on PBS2 and HOG1 protein kinases for osmotic induction. DDR48 requires 1 M NaCl for maximum induction and its expression in independent of PBS2 and HOG1 protein kinases and less sensitive to protein kinase A. PAI3 and SIP18 are as dependent on the above protein kinases as ALD2. Deletion analysis indicates that most of the regulation of the ALD2 promoter is mediated by a negative element counteracted by osmotic stress.
Mol
Microbiol 1995 Aug
PMID:A genomic locus in Saccharomyces cerevisiae with four genes up-regulated by osmotic stress. 880 20
Nerve growth factor (NGF) is a neurotrophic factor for basal forebrain cholinergic neurons, a population that degenerates and dies in Alzheimer's disease (AD). It has been suggested that NGF be used to treat AD patients. However, in vivo administration of NGF to the developing hamster brain was shown to induce the expression of the beta-amyloid precursor protein (beta APP) gene. The association of alterations in beta APP gene expression with AD-like neuropathological changes and cognitive impairment in animals, and with AD-like neurodegeneration in Down syndrome patients suggests that NGF-mediated increases in beta APP expression could negate or attenuate NGF's neurotrophic activity in AD treatment trials. The present study was undertaken to explore further the influence of NGF on beta APP expression, and to determine which, if any, of the beta APP mRNAs is altered in response to NGF treatment. We first examined the spatiotemporal pattern of beta APP-695 and Kunitz
protease inhibitor
(KPI)-containing beta APP mRNA expression in the rat brain. Specific oligonucleotide probes were used to show that these mRNAs are present during embryonic development. In addition, we evaluated postnatal expression in nine brain regions and showed that beta APP mRNAs were readily detected in all regions at postnatal day 2. In human brain, the relative levels of beta APP-695 and beta APP-KPI mRNA and their protein are discordant, in that the level of beta APP-695 mRNA is slightly higher than that of beta APP-KPI, but beta APP-KPI protein predominates. In contrast, the several-fold excess of beta APP-695 mRNA relative to beta APP-KPI mRNA in the rat brain was also reflected at the protein level. Surprisingly, administration of exogenous NGF failed to affect rat beta APP mRNA levels either in vitro or during postnatal development in vivo.
Brain Res
Mol
Brain Res 1996 Jul
PMID:A comprehensive study of the spatiotemporal pattern of beta-amyloid precursor protein mRNA and protein in the rat brain: lack of modulation by exogenously applied nerve growth factor. 880 27
Kallmann syndrome is characterized by hypogonadotropic hypogonadism and anosmia and caused by a defect of migration and targeting of gonadotropin-releasing hormone-secreting neurons and olfactory axons during embryonic development. We previously cloned the gene responsible for the X-linked form of the disease encoding a 680 amino acid protein, KAL, which displays the unusual combination of a
protease inhibitor
domain with fibronectin type III repeats. Previous expression studies by northern blot and RNA in situ hybridization in human and chick indicated that the gene is expressed at very low levels in the olfactory bulb during development. Therefore, low abundance of the protein has hampered a detailed biochemical characterization. By overexpressing both the human and chick KAL cDNAs in eukaryotic cells, we now provide evidence that KAL is a glycosylated peripheral membrane protein with an apparent molecular weight of approximately 100 kDa. We show that this 100 kDa protein is proteolytically processed on the cell membrane to yield a 45 kDa diffusible component, which is detectable with an antisera against the C-terminal part of the protein and binds tightly to cell surfaces. These data provide a first step toward understanding KAL function in neuronal interactions and neurite extension in the olfactory bulb and suggest that KAL might be a diffusible chemoattractant molecule for olfactory axons.
Hum
Mol
Genet 1996 Aug
PMID:The Kallmann syndrome gene product expressed in COS cells is cleaved on the cell surface to yield a diffusible component. 884 28
Alternative splicing of beta-amyloid precursor protein (APP) RNA generates APP isoforms with or without a Kunitz
protease inhibitor
(KPI) domain. Previously, we showed that KPI (+) APP RNA, but not KPI (-) APP RNA, is upregulated in response to experimental lesions in which neurotoxicity is dependent on NMDA receptor activation and in Alzheimer's disease hippocampus. Recent studies by Mucke et al. (1995) showed that neuronal expression of human KPI (+) APP, but not KPI (-) APP, in transgenic mice is neuroprotective against experimental lesions. In this study we examined the direct effects of the excitotoxic amino acid Glu on alternatively, spliced APP RNAs and the corresponding protein isoforms in cultured rat cortical neurons. Glu treatment rapidly induced (4.5 h) KPI (+) APP RNA but not KPI (-) APP RNA. Induction of KPI (+) RNA preceded Glu-induced neuronal cell death and was partially blocked by an NMDA-receptor antagonist. In contrast to the RNA, cellular levels of KPI (+) APP were not changed by 4.5 h of Glu treatment. Instead, the cellular full-length form of the protein KPI (-) APP was reduced by approximately 50% after 2 h of Glu treatment and remained depleted after 24 h of treatment. Cellular levels of KPI (+) forms of amyloid precursor-like protein 2 (APLP2) were not changed by Glu treatment. Our data are consistent with the hypothesis that sustained NMDA-receptor activation can regulate alternative splicing of the APP pre-mRNA in neurons.
J
Mol
Neurosci 1995
PMID:Beta-amyloid precursor protein (APP) and APP-RNA are rapidly affected by glutamate in cultured neurons: selective increase of mRNAs encoding a Kunitz protease inhibitor domain. 886 Feb 37
Insulin receptor substrate-1 (IRS-1) is a protein expressed in 3T3-L1 adipocytes that is involved in most, if not all of the biological responses to insulin. Chronic exposure of these cells to insulin down-regulates IRS-1 by stimulating its degradation (Rice, K.M., Turnbow, M.A. and Garner, C.W. (1993) Biochem. Biophys. Res. Commun. 190, 961-967). This insulin-induced down-regulation of IRS-1 was totally abolished by BAPTA-AM (cell-permeable calcium chelator), E-64d (cell-permeable thiol
protease inhibitor
), Cbz-Leu-Nleu-H and Cbz-Leu-Leu-Tyr-CHN2 (selective cell-permeable calpain inhibitor peptides). Calpastatin (specific calpain inhibitor protein) also inhibited the insulin-induced down-regulation of IRS-1 in transiently permeabilized cells. In addition, 3T3-L1 adipocytes express endogenous calpain which can degrade IRS-1 in cell-free extracts. These results suggest that the insulin-induced down-regulation of IRS-1 in 3T3-L1 adipocytes is mediated by a calcium-dependent thiol protease which is sensitive to inhibition by calpain inhibitors.
Mol
Cell Endocrinol 1996 Aug 30
PMID:The insulin-induced down-regulation of IRS-1 in 3T3-L1 adipocytes is mediated by a calcium-dependent thiol protease. 889 50
<< Previous
1
2
3
4
5
6
7
8
9
10
Next >>