Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glandular or tissue kallikrein and prostate-specific antigen (PSA) are members of the human kallikrein (KLK) multigene family of enzymes. Various components of the glandular kallikrein-kinin system (kallikrein, low molecular weight kininogen, bradykinin) have been recently shown to be present or active in the human endometrium. We have used the reverse transcriptase-polymerase chain reaction (RT-PCR) with universal KLK primers to demonstrate kallikrein gene expression in this tissue. On Southern blot analysis with gene-specific oligonucleotide probes, we have detected expression of the three human KLK genes--KLK1 (kallikrein), KLK2 (or hGK1) and KLK3 (PSA). The expression of KLK1 and KLK3 was further confirmed by sequence analysis of three different endometrial PCR products. These findings confirm the presence of a local kallikrein-kinin system in the human endometrium. The significance of the novel expression of KLK2 and KLK3 (PSA), previously thought to be prostate-specific genes, in the endometrium is unclear. This family of enzymes must now be considered potential local regulators of uterine function.
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PMID:Glandular kallikreins and prostate-specific antigen are expressed in the human endometrium. 751 92

Uterine homogenates of cycling and early pregnant Sprague Dawley rats and purified rat urinary kallikrein showed similar curves of displacement of 125I-kallikrein binding to a polyclonal antibody. Uterine kallikrein concentration measured by RIA was 8.7 +/- 2 SEM ng/g wet weight during the cycle (n = 6 in diestrus and metestrus) and 20.8 +/- 2 SEM (n = 7) ng/g wet weight on Day 7 of pregnancy (P7) (p < 0.001). On P7, kallikrein concentration was increased 12.4-fold in the implantation nodes, as compared to the interimplantation segments. Uterine homogenates of rats on P7, submitted to DEAE-cellulose chromatography and Sephadex gel filtration, yielded two fractions containing kallikrein immunoreactivity and kininogenase activity, with molecular masses that ranged from 120-125 kDa and 39-43 kDa, respectively. In the RIA, both fractions displayed parallelism with purified kallikrein. Enzymatic activity was expressed after activation by trypsin. It was inhibited by aprotinin, PMSF, p-amino-benzamidine, and leupeptin, but not by soybean or ovomucoid trypsin inhibitors. Kallikrein mRNA was demonstrated by reverse transcriptase/polymerase chain reaction in uteri of nonpregnant and P7 rats. These results show that rat uterus synthesizes one or more serine proteases that are immunologically and enzymatically related to tissue kallikrein in the implantation node on P7--determined both by an increment of whole uterus kallikrein content and a depletion of the interimplantation segments--suggests that kallikrein may play a role in the vasoactive changes of implantation.
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PMID:Uterine kallikrein in the early pregnant rat. 821 45

Expression of tissue kallikrein in human neutrophils has been suggested by previous studies using enzymatic and immunochemical techniques. Secretion of this potent biological factor by neutrophils would be of marked significance in the inflammatory process. The present study utilized the polymerase chain reaction following reverse transcriptase generation of total neutrophils cDNA to demonstrate the presence of tissue kallikrein mRNA in the human neutrophils. In addition, use of sequence-specific primers demonstrated the presence of mRNA for the hGK-1 gene, but not for the hPK gene product or the gene for prostate-specific antigen. These results confirm that tissue kallikrein is present in neutrophils and may be secreted as part of the inflammatory process.
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PMID:Identification of tissue kallikrein messenger RNA in human neutrophils. 848 May 36

This study examined the expression and presence of components of the kallikrein-kinin system in human term placenta. Immunohistochemical studies localized H-kininogen and plasma prekallikrein/plasma kallikrein to endothelial cells of placental villous capillaries. In larger placental blood vessels and umbilical cord, neither kininogens nor kallikreins were detected. High (H) and low (L) molecular weight kininogen, plasma prekallikrein and plasma kallikrein were detected by Western blot analysis in human term placenta and in maternal and fetal blood, whereas tissue kallikrein was not. Furthermore, mRNA of plasma prekallikrein was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in placental homogenates, while mRNA of H-kininogen, L-kininogen and tissue kallikrein was not. Because H-kininogen and plasma prekallikrein circulate in a complexed form, we suggest that endothelial cells bind kininogen and plasma prekallikrein in which they are secreted by the fetal liver from fetal blood. The co-localization of kininogen and plasma prekallikrein/plasma kallikrein suggests that kinins could be generated locally in placental capillaries. When released, they may play a role in regulating placental blood flow and transplacental transport of substrates and metabolites.
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PMID:High and low molecular weight kininogen and plasma prekallikrein/plasma kallikrein in villous capillaries of human term placenta. 876 66

The expression of the tissue kallikrein gene is tissue-specific and exhibits a complex pattern of transcriptional and post-translational regulation. Information concerning the mechanism of its tissue-specific expression has been limited owing to the lack of suitable cell lines for the expression study. We approached this problem by introducing human tissue kallikrein gene constructs into mouse embryos, creating transgenic lines carrying its coding sequence with varying lengths of the promoter region. One construct (PHK) contained 801 bp in the 5'-flanking region and two deletion constructs contained either 302 bp (D300) or 202 bp (D200) of the promoter region. The expression of human tissue kallikrein in these transgenic mice was monitored by Northern blot, reverse transcriptase-PCR followed by Southern blot, and radioimmunoassay. In all three lines, human tissue kallikrein was expressed predominantly in the pancreas and at lower levels in other tissues, including salivary gland, kidney and spleen. This pattern was similar to that of tissue kallikrein expression in human tissues. The D300 line has higher levels of transgene expression than the D200 and PHK lines. The results indicate that the 202 bp segment immediately upstream of the translation starting site is sufficient to direct a tissue-specific expression pattern of the human tissue kallikrein gene, and that regulatory elements might exist between -801 and -202.
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PMID:Tissue-specific expression and promoter analyses of the human tissue kallikrein gene in transgenic mice. 922 35