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)

We have used reverse transcriptase-polymerase chain reaction (RT-PCR) analysis and insitu hybridization to further define the tissue and cell-specific pattern of expression of the rat kallikrein gene family. rKlk1 gene expression has been unequivocally demonstrated in the rat heart, ovary and testis. Similarly, rKlk3, 4 and 9 gene expression has been demonstrated in the testis/ovary, heart and testis respectively. Insitu hybridization has identified the expression of kallikrein gene family members to specific cell-types in the rat ovary (granulosa cell) and testis (germ cell).
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PMID:A re-evaluation of the tissue-specific pattern of expression of the rat kallikrein gene family. 146 85

A method is described to clone cDNAs corresponding to the 5' end of specific mRNAs which are absent from cDNA libraries. A segment is excised from the 5' end of a previously cloned truncated cDNA and hybridized to total polyadenylated RNA. The hybridized primer is extended using reverse transcriptase, tailed with deoxycytidine, and the second strand synthesized using oligo (dG)10-16 as a primer. The primer-extended double-stranded cDNA is cloned into pBR322 by dC-dG homopolymeric tailing. This method has been successful for cloning a 398 bp cDNA fragment corresponding to the entire 5' end of rat pancreatic elastase I mRNA, a prominent pancreatic mRNA, and a 510 bp fragment encoding the 5' end of kallikrein mRNA, a lower abundant pancreatic mRNA.
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PMID:Cloning cDNAs corresponding to the 5' end of messenger RNAs using specific DNA primers. 657 Jun 93

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

The glandular or tissue kallikreins are a multigene family of serine proteases, of which 13 genes (rKLK1-13) have been identified in the rat and are expressed in a wide variety of tissues. Kallikrein-like enzyme activity has been detected during the periovulatory period in the gonadotropin-primed immature female rat ovary and suggested to play a role in the inflammatory-like response at ovulation. In this study, we examined whether this enzyme activity was due to local expression of a rat KLK gene family member. Ovarian RNA, prepared from gonadotropin-treated animals, was assessed for rKLK gene expression by reverse transcriptase-polymerase chain reaction (RT-PCR) with universal rKLK primers derived from highly conserved regions in the rat KLK genes. Southern blot analysis of the RT-PCR products, using oligonucleotide probes specific for the individual genes, indicated that five rKLK gene family members, rKLK1 (encoding true kallikrein), rKLK3, rKLK7, rKLK8, and rKLK9, were expressed at varying levels in the ovaries of both untreated control and gonadotropin-treated immature female rats. The identities of these five rKLK messenger RNAs were further confirmed by DNA sequence analysis of the PCR products. In situ hybridization of gonadotropin-treated ovaries localized rKLK3 and rKLK7 gene expression to the luteinizing granulosa cells of periovulatory follicles. In an enriched population of nonluteinizing granulosa cells prepared from estrogen-primed animals, we also demonstrated rKLK3, rKLK7, rKLK9, and rKLK12 (but not rKLK1 or rKLK8) expression, whereas all six genes were expressed in the ovaries of these animals. In summary, we have reported the expression of six KLK gene family members in the rat ovary and localized this expression primarily to the granulosa cell. The potential roles of these enzymes in ovulation or other aspects of ovarian, particularly granulosa cell, function are yet to be elucidated.
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PMID:Kallikrein gene family expression in the rat ovary: localization to the granulosa cell. 786 67

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

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

Human high (H) and low (L) molecular weight kininogens are encoded by distinct mRNAs derived by alternative splicing from a single kininogen gene. Previous studies have demonstrated the presence of L-kininogen but not of H-kininogen in the distal nephron structures of the kidney. Using the highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) we have been able to demonstrate the expression of both H-kininogen mRNA and L-kininogen mRNA in kidney and liver. The presence of H- and L-kininogen antigen was shown immunohistochemically by applying specific antibodies that discriminate between the two types of kininogens. Immunoreactive kininogens were localized in the cortical and medullary collecting ducts. Our results indicate that both types of kinin-bearing kallikrein substrates are expressed in the human kidney where they might contribute to the suggested roles of the kallikrein-kinin system in the regulation of renal blood flow and electrolyte excretion.
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PMID:Expression and cellular localization of kininogens in the human kidney. 880 75

When used alone, prostate-specific antigen (PSA) is not sufficiently sensitive or specific to consider it an ideal tool for the early detection or staging of prostate cancer. To optimize the use of PSA, the concepts of PSA velocity, PSA density, and age-related PSA values were developed. Although PSA velocity provides excellent results, its determination requires three PSA values over a 2-year period. The value of PSA density rests on the accurate determination of prostatic volume by transurethral ultrasound (TRUS), which is examiner-dependent. Age-specific reference ranges appear to be more sensitive in men under age 60 than in those over 60. The molecular forms of PSA, especially the percentage of free PSA, seem to be useful tools for the detection of prostate cancer in men with slightly elevated total PSA. New molecular techniques, such as the reverse transcriptase-polymerase chain reaction (RT-PCR), enable the detection of minimal amounts of PSA messenger RNA (mRNA). Human kallikrein 2 (hK2), a serine protease closely related to PSA that also is expressed predominantly in the prostate, may be a new marker for prostate cancer.
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PMID:Prostate-specific antigen: what's new in 1997. 968 75

Although prostate-specific antigen (PSA), or human kallikrein 3, is the most valuable tool available for the diagnosis and management of prostate cancer, as currently used it is insufficiently sensitive and specific for early detection or staging of the malignancy. Many new concepts have been introduced in order to optimize the clinical use of PSA measurements, but each one has its own drawbacks. The molecular forms of PSA, especially the free PSA, seem to be useful for the detection of prostate cancer in men with PSA concentrations falling in the 4-10 microg/l range. New molecular techniques, such as reverse transcriptase polymerase chain reaction for the detection of minimal amounts of PSA messenger RNA and prostate-specific membrane antigen, offer new promise for the prognosis and possibly staging of prostate cancer. On the other hand, human kallikrein 2, a serine protease closely related to PSA that is also expressed predominantly in the prostate, may be a new adjuvant marker for prostate cancer. As for its biological functions, PSA can no longer be regarded as a specific prostate molecule associated mainly with semen liquefaction when it has a possible role as a prognostic indicator in female breast cancer. The biological role of PSA in normal tissues and tumors may be much more complex than previously thought and requires further investigation.
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PMID:Prostate-specific antigen and new related markers for prostate cancer. 980 90

Tissue kallikrein (TK) and kinin receptors have been immuno-localized in various areas of the human nervous system, suggesting that the kallikrein-kinin system (KKS) may be functionally active in the brain. The aim of this study was to determine the cellular expression of TK and kinin B1 and B2 receptor mRNAs in specific regions of the human brain by in situ reverse transcriptase polymerase chain reaction. Autopsy samples of the brain, spinal cord, kidney and salivary gland were embedded in paraffin. Sections (5 microm), adhered onto silane coated glass slides, were treated with Proteinase K and DNase, followed by reverse transcription polymerase chain reaction with specific KKS primers and digoxigenin-dUTP. Detection of the digoxigenin-label demonstrated localization of TK, B1 and B2 mRNAs in the cytoplasm of some neuronal cell bodies in the hypothalamus, thalamus, frontal cortex and spinal cord. TK mRNA was also observed in the ependymal cells lining the cerebral ventricles and epithelial cells of the choroid plexus. In the choroid plexus, only B1 gene expression was observed in some choroidal epithelial cells while no B2 labeling was detected. The identification of mRNAs to TK, B1 and B2 kinin receptors in human nervous tissue supports previous evidence for the presence of the KKS in the brain and confirms localized protein synthesis.
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PMID:Detection of tissue kallikrein and kinin B1 and B2 receptor mRNAs in human brain by in situ RT-PCR. 1138 57


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