Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01034 (cystatin C)
 3,397 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As a result of examining regional-specific gene expression in the mouse epididymis, a novel cystatin-related epididymal specific (CRES) gene was identified. Substantial homology between the CRES gene and members of the cystatin family of cysteine proteinase inhibitors was observed at the amino acid level. This homology included the presence of four highly conserved cysteine residues in exact alignment with the cystatins as well as other regions of sequence characteristic of the cystatins. However, unlike the cystatins, the CRES gene does not contain specific highly conserved sequence motifs thought to be necessary for cysteine proteinase inhibitory activity. Also, in contrast to the ubiquitous expression of the cystatin C gene, Northern blot analysis and in situ hybridization demonstrated that the CRES gene is very restricted in its expression. The 0.75-kilobase CRES transcript is dramatically restricted to the very proximal caput region of the epididymis with 15- to 20-fold less expression in the testis and no expression detected in any of the other 24 tissues examined. In addition, the CRES transcript disappears 2-3 weeks after castration, suggesting a dependence on androgens. However, its expression remained undetectable even after the administration of testosterone or dihydrotestosterone. Unilateral castration also resulted in the disappearance of the CRES mRNA from the castrate epididymis, but not from the intact epididymis, suggesting that testicular factors or hormones other than androgens may be involved in the regulation of CRES gene expression. Therefore, the unique sequence of the CRES gene as well as its highly restricted expression and unusual regulation by the testis suggests that it has a very specialized role in the epididymis.
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PMID:The CRES gene: a unique testis-regulated gene related to the cystatin family is highly restricted in its expression to the proximal region of the mouse epididymis. 128 Mar 28

A new member of the human cystatin multigene family has been cloned from a genomic library using a cystatin C cDNA probe. The complete nucleotide sequence of a 4.3-kilobase DNA segment, containing a complete gene with structure very similar to those of known Family 2 cystatin genes, was determined. The novel gene, called CST4, is composed of three exons and two introns. It contains the coding information for a protein of 142 amino acid residues, which has been tentatively called cystatin D. The deduced amino acid sequence includes a putative signal peptide and presents 51-55% identical residues with the sequences of either cystatin C or the secretory gland cystatins S, SN, or SA. The cystatin D sequence contains all regions of relevance for cysteine proteinase inhibitory activity and also the 4 cysteine residues that form disulfide bridges in the other members of cystatin Family 2. Northern blot analysis revealed that the cystatin D gene is expressed in parotid gland but not in seminal vesicle, prostate, epididymis, testis, ovary, placenta, thyroid, gastric corpus, small intestine, liver, or gall-bladder tissue. This tissue-restricted expression is in marked contrast with the wider distribution of all the other Family 2 cystatins, since cystatin C is expressed in all these tissues and the secretory gland cystatins are present in saliva, seminal plasma, and tears. Cystatin D, being the first described member of a third subfamily within the cystatin Family 2, thus appears to have a distinct function in the body in contrast to other cystatins.
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PMID:Structure and expression of the gene encoding cystatin D, a novel human cysteine proteinase inhibitor. 193 5

Tissue patterns of gene expression were analyzed by measuring mRNA levels and incorporation of radioactive amino acids for cystatin C and beta 2-microglobulin, the two extracellular proteins in the brain with the highest ratio of concentration in cerebrospinal fluid over that in blood plasma. The primary structure of rat cystatin C mRNA from choroid plexus was determined by nucleotide sequencing of cloned cDNA and the tissue patterns of gene expression were analysed by RNA blot analysis and in situ hybridization. Cystatin C was found to be composed of 120 amino acids and to contain a potential site for N-linked glycosylation. The tissue with the highest cystatin C mRNA level was the choroid plexus of the brain. Cystatin C mRNA was also detected in lower levels in other areas of the brain, testis, epididymis, seminal vesicles, prostate, ovary, submandibular gland, and, in trace amounts, in liver. Choroid plexus pieces in culture secreted radioactive cystatin C when incubated with radioactive leucine. Rat beta 2-microglobulin cDNA was cloned and identified by nucleotide sequencing and comparison of the obtained sequence with that of mouse and human beta 2-microglobulin cDNA. Tissue levels of beta 2-microglobulin mRNA in the rat were measured by hybridization to rat beta 2-microglobulin cDNA. The highest levels of beta 2-microglobulin mRNA were observed in liver and choroid plexus. Other parts of the brain and testis contained lower levels of beta 2-microglobulin mRNA.
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PMID:The cDNA structure and expression analysis of the genes for the cysteine proteinase inhibitor cystatin C and for beta 2-microglobulin in rat brain. 268 74

The specific inhibitor of cysteine proteinases, cystatin C, was purified from ram rete testis fluid and the conditioned medium of Sertoli cells. This molecule associated with sheep liver cathepsin L at one of the fastest rates ever described for a proteinase/inhibitor interaction (1.75 +/- 0.20 x 10(8) M-1.s-1). But the association rate constant for the interaction of cathepsin L with alpha 2-macroglobulin, a non-specific inhibitor of proteinases, was also extremely high (8.8 +/- 0.75 x 10(6) M-1.s-1). Cathepsin L complexed with alpha 2-macroglobulin was protected from inhibition by type 2 and type 3 cystatins. The data indicate that cystatin C is the most potent inhibitor of cathepsin L in mammalian male genital tract fluids, whereas alpha 2-macroglobulin may act as a terminal acceptor of this enzyme. These inhibitors could therefore inhibit the activated form of procathepsin L which may appear during the complex process of spermatozoa production and maturation in the testis and epididymis.
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PMID:Interactions between ovine cathepsin L, cystatin C and alpha 2-macroglobulin. Potential role in the genital tract. 906 57

Cystatin (CST)11, a novel member of the CST type 2 family of cysteine protease inhibitors, was identified in Macaca mulatta epididymis by subtractive hybridization cloning. The human CST11 gene on chromosome 20p11.2 is located near three other CST genes expressed predominantly in the male reproductive tract. The CST11 gene spans three exons, a structure similar to that of other CST family 2 genes. An exon 2-deleted alternative transcript (CST11Delta2) was also identified. CST11 mRNA is expressed only in the epididymis as judged by Northern blot hybridization and is androgen regulated. The protein is most abundant in the initial segment, but is detected throughout the epididymis and on ejaculated human sperm. The calculated tertiary structure of CST11 reveals that the three regions corresponding to the protease inhibitory wedge of CST3 are similarly juxtaposed in CST11, consistent with protease inhibitor function. Intact and exon 2-deleted CST11 recombinant proteins were tested for antibacterial activity. After a 2-h incubation of Escherichia coli with 50 microg/ml recombinant CST11 or CST11Delta2, bacterial colony-forming units were reduced to 30% of control, indicating that both forms have antimicrobial activity.
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PMID:Cystatin 11: a new member of the cystatin type 2 family. 1207 14

The CRES (cystatin-related epididymal spermatogenic) protein defines a new subgroup in the family 2 cystatins of the cystatin superfamily of cysteine protease inhibitors. However, unlike the ubiquitous expression of cystatin C, the Cres gene is preferentialy expressed in postmeiotic germ cells, the proximal caput epididymidis, and anterior pituitary gonadotrophs. Furthermore, CRES protein lacks two of the three consensus sites necessary for the cystatin inhibition of C1 cysteine proteases. Therefore, CRES may perform unique and tissue-specific functions in the reproductive and neuroendocrine systems. In the present review, we describe our studies on: 1. the Cres gene promoter and the transcriptional regulatory protein and their associated DNA binding sites that may be important for tissue-specific expression; and 2. the biochemical function of CRES protein. In brief, Northern blot, gel shift analyses, and transient transfection assays demonstrated that the C/EBP beta (CCAAT/enhancer binding protein) transcription factor is the predominant C/EBP family member expressed in the epididymis and gonadotroph cells and is necessary for high levels of Cres expression in these two tissues. In other studies, analyses of transgenic mice expressing a CAT reporter gene driven by 1.6 kb of Cres promoter revealed CAT mRNA and protein only in the germ cells. These studies suggest that the 1.6 kb of Cres 5' flanking sequence contains the required DNA elements for expression in the testis, but lacks the elements to correctly target expression of the reporter gene in the epididymis. Alternatively, repressor elements may be present. Finally, in vitro protease assays were performed to determine if CRES functions as a protease inhibitor. In contrast to cystain C, CRES did not inhibit the C1 cysteine protease papain but rather inhibited at nanomolar concentrations the serine protease PC2, a prohormone processing enzyme. Therefore, CRES is a new cross-class inhibitor that may regulate PC2 of PC2-like proteases and suggests a role for CRES in the regulation of prohormone and proprotein processing.
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PMID:[Cres (cystatin-related epididymal spermatogenic) gene regulation and function]. 1247 14

Cystatin C displays the strongest inhibitory activity of all cystatins toward lysosomal cysteine proteases in general and has a widespread distribution in human tissues and body fluids, including seminal plasma. The aim of this study was to investigate the distribution of cystatin C in the male reproductive system. Immunohistochemistry revealed a widespread distribution of cystatin C in normal tissues from the testis, epididymis, vas deferens, seminal vesicle, and prostate gland. Immunoreactive cystatin C was localized in basal and secretory epithelial cells, but also in neuroendocrine cells in the prostate, identified by immunostaining for chromogranin A. On adjacent tissue sections, we demonstrated local production of cystatin C utilizing nonradioactive in situ hybridization with a 201-base-long digoxigenin-labeled antisense RNA probe specific for the cystatin C transcript. Staining patterns obtained by immunohistochemistry and in situ hybridization correlated well. Enzyme-linked immunosorbent assay for quantitative analysis of cystatin C demonstrated that cystatin C was present at high concentrations in tissue homogenates from all locations investigated, compared to liver, muscle, spleen, and other general tissues. Western blotting of tissue homogenates revealed a predominant 15-kd cystatin C immunoreactive component in accordance with previous findings in other organs. Quantitative real-time polymerase chain reaction analysis to determine messenger RNA levels in whole tissue extracts showed that the cystatin C gene is highly expressed in the seminal vesicles and the prostate gland, indicating that the major amount of cystatin C in the male reproductive organs and seminal plasma is produced by cells in these 2 tissues. It is concluded that cystatin C is highly expressed and widely distributed throughout the male genital tract, suggesting that cystatin C is an important regulator for normal and pathological proteolysis in the male reproductive system.
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PMID:Cystatin C is highly expressed in the human male reproductive system. 1522 45

The epididymal lumen represents a unique extracellular environment because of the active sperm maturation process that takes place within its confines. Although much focus has been placed on the interaction of epididymal secretory proteins with spermatozoa in the lumen, very little is known regarding how the complex epididymal milieu as a whole is maintained, including mechanisms to prevent or control proteins that may not stay in their native folded state following secretion. Because some misfolded proteins can form cytotoxic aggregate structures known as amyloid, it is likely that control/surveillance mechanisms exist within the epididymis to protect against this process and allow sperm maturation to occur. To study protein aggregation and to identify extracellular quality control mechanisms in the epididymis, we used the cystatin family of cysteine protease inhibitors, including cystatin-related epididymal spermatogenic and cystatin C as molecular models because both proteins have inherent properties to aggregate and form amyloid. In this chapter, we present a brief summary of protein aggregation by the amyloid pathway based on what is known from other organ systems and describe quality control mechanisms that exist intracellularly to control protein misfolding and aggregation. We then present a summary of our studies of cystatin-related epididymal spermatogenic (CRES) oligomerization within the epididymal lumen, including studies suggesting that transglutaminase cross-linking may be one mechanism of extracellular quality control within the epididymis.
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PMID:Extracellular quality control in the epididymis. 1758 87

CRES (cystatin-related epididymal spermatogenic), a member of the cystatin superfamily of cysteine protease inhibitors, is expressed in the epididymis and spermatozoa, suggesting specialized roles in reproduction. Several cystatin family members oligomerize, including cystatin C that forms amyloid deposits associated with cerebral amyloid angiopathy. Our studies demonstrate that CRES also forms oligomers. Size exclusion chromatography revealed the presence of multiple forms of CRES in the epididymal luminal fluid, including SDS-sensitive and SDS-resistant high molecular mass complexes. In vitro experiments demonstrated that CRES is a substrate for transglutaminase and that an endogenous transglutaminase activity in the epididymal lumen catalyzed the formation of SDS-resistant CRES complexes. The use of a conformation-dependent antibody that recognizes only the oligomeric precursors to amyloid, negative stain electron microscopy, and Congo Red staining showed that CRES adopted similar oligomeric and fibrillar structures during its aggregation as other amyloidogenic proteins, suggesting that CRES has the potential to form amyloid in the epididymal lumen. The addition of transglutaminase, however, prevented the formation of CRES oligomers recognized by the conformation antibody by cross-linking CRES into an amorphous structure. We propose that transglutaminase activity in the epididymal lumen may function as a mechanism of extracellular quality control by diverting proteins such as CRES from the amyloidogenic pathway.
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PMID:Oligomerization and transglutaminase cross-linking of the cystatin CRES in the mouse epididymal lumen: potential mechanism of extracellular quality control. 1785 42

Cystatin-related epididymal spermatogenic (CRES) protein, a member of the cystatin superfamily of cysteine protease inhibitors (also known as CST8), exhibits highly specific, age-dependent expression in mouse testis and epididymis. The CRES protein possesses four highly conserved cysteine residues which govern the overall conformation of the cystatins through the formation of two disulfide bonds. Previous studies have revealed that other cystatin family members, such as cystatin 3 and cystatin 11, show antibacterial activity in vitro. This prompted us to investigate the potential antimicrobial activity of the CRES protein. Colony forming assays and spectrophotometry were used to investigate the effects of recombinant CRES protein on Escherichia coli (E. coli) and Ureaplasma urealyticum (Uu), respectively, in vitro. After incubation of E. coli with CRES recombinant protein fused with glutathione-S-transferase (GST), a substantial decrease in colony forming units was observed, and the effect was dose and time dependent. Furthermore, it took longer for Uu to grow to plateau stage when incubated with GST-CRES recombinant protein compared with the control GST. The antibacterial and Anti-Uu activities were not impaired when the cysteine residues of CRES protein were mutated, indicating that the antimicrobial effect was not dependent on its disulfide bonds. Functional analysis of three CRES polypeptides showed that the N-terminal 30 residues (N30) had no antimicrobial activity while N60 showed similar activity as full-length CRES protein. These results suggest that the active center of CRES protein resides between amino acid residues 31 and 60 of its N-terminus. Mechanistically, E. coli membrane permeabilization was increased in a dose-dependent manner, and macromolecular synthesis was inhibited on treatment with GST-CRES. Together, our data on the antimicrobial activities of CRES protein suggest that it is a novel and innate antimicrobial protein which protecting the male reproductive tract against invading pathogens.
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PMID:Antimicrobial activity and molecular mechanism of the CRES protein. 2318 54


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