Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q9UIJ5 (Rec)
 58,342 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Upon exposure to the carcinogens N-acetoxy-N-2-acetylaminofluorene and 7-bromomethyl-benz[a]anthracene, which bind covalently to DNA, ether-permeabilized (nucleotide-permeable) Escherichia coli wild-type cells responded with DNA excision repair. This repair was missing in mutants carrying defects in genes uvrA, uvrB and uvrC, whereas it was present in uvrD and several rec mutants. Enzymic activities involved were identified by measuring repair polymerization and size reduction of denatured DNA. 1. An easily measurable effect in E. coli wild-type cells was carcinogen-induced repair polymerization. When initiated by N-acetoxy-N-2-acetylaminofluorene or 7-bromomethyl-benz[a]anthracene, it depended upon an ATP-requiring step; CTP, GTP or UTP did not substitute for ATP. DNA repair synthesis was inhibited by p-chloromercuribenzoate and quinacrine. In uvrA, uvrB and uvrC mutants no carcinogen-stimulated DNA synthesis could be detected, indicating that steps involved in pyrimidine dimer excision are also involved in chemorepair. In recA, recB and recC mutant cells, repair synthesis was stimulated by the carcinogens to a normal extent. This evidence excludes the ATP-dependent recB,C deoxyribonuclease and recA gene products as playing an important role in carcinogen-induced excision repair. polA1 cells showed drastically reduced levels of rapair polymerization, indicating that DNA polymerase I is the main polymerizing enzyme. 2. As determined by DNA size reduction in alkaline sucrose gradients, the arylalkylating carcinogens caused endonucleolytic cleavage of endogenous DNA in wild-type cells. This incision step was most effectively performed in the presence of ATP; UTP, CTP and GTP were only slightly effective. Incision was inhibited by p-chloromercuribenzoate and quinacrine. When exposed to the arylalkylating carcinogens, uvrA, uvrB and uvrC mutant cells did not perform the incision step in the presence of ATP, suggesting the involvement of the respective gene products in the initiation of chemorepair.
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PMID:Carcinogen-induced DNA repair in nucleotide-permeable Escherichia coli cells. Analysis of DNA repair induced by the carcinogens N-acetoxy-N-2-acetylaminofluorene and 7-bromomethyl-benz(a)anthracene. 76 31

Non-radioactive detection of mRNA with in situ hybridization histochemistry has emerged as an important new technology for the study of gene expression. Quantitative in situ hybridization studies have generally relied upon counting of autoradiographic grains in the emulsion overlying cells containing hybridized, radioactively labeled probe. However, such high resolution studies require tedious grain counting over individual cells, frequently in addition to weeks of exposure to nuclear emulsion. The present report describes a quantitative, non-radioactive approach to the detection of a specific mRNA in the brain with the advantages of comparatively rapid tissue processing and computerized image analysis. The validity of this approach was tested by measuring the haloperidol-induced increase in the level of preproenkephalin mRNA in striatal sections of the rat brain using an RNA probe labeled with digoxigenin-11-UTP. Detection of probe hybridized to tissue sections was carried out enzymatically following complex formation with an antidigoxigenin-alkaline phosphatase conjugate. Using computerized image analysis, it was found that chronic treatment of rats with haloperidol resulted in a 50 +/- 6% increase in striatal neuronal optical density, a value in good agreement with previous studies using low-resolution radioactive methods, showing a 30-80% increase in striatal preproenkephalin mRNA hybridization signal.
Anat Rec 1991 Dec
PMID:Quantitative non-radioactive in situ hybridization of preproenkephalin mRNA with digoxigenin-labeled cRNA probes. 179 81

Gene expression for calbindin-D28k, the 28,000 relative molecular mass vitamin D-dependent calcium-binding protein, was measured in cells of the murine nephron by in situ hybridization on tissue sections (hybridization cytochemistry). Radiolabeled (35S-UTP), single-stranded RNA complementary to calbindin-D28k-mRNA (probe RNA) was prepared from linearized cDNA template and used for the hybridizations. Autoradiography was carried out and cellular levels of hybridization signal (silver grains) were quantified. After correction for background the concentration of silver grains was more than 350% greater in the distal tubule than in either the proximal tubule or the glomerulus. The relative cellular level of mRNA in the cytoplasm, as reflected in silver grains/cell, of the distal tubules with probe RNA was 3.4 times greater than that with control RNA. Cells of the distal tubule were the only apparent sites of specific hybridization with probe RNA. The presence of calbindin-D28k-mRNA in the distal tubule corresponded to the localization of calbindin-D28k by immunocytochemistry.
Anat Rec 1990 Jun
PMID:Cellular gene expression for calbindin-D28k in mouse kidney. 235 3

The large intestine of mammals has long been viewed as an osmoregulatory organ, and evidence suggests that fluid and solute transport mechanisms within the intestine are heterogeneous, varying depending on the particular segment involved. Variations in function are often matched by morphological correlates, but despite the widespread use of rabbit large intestine as an experimental model, there is a lack of knowledge about the cellular makeup and dynamics in the colonic mucosal epithelium. The presence of mitotic figures and immunohistochemical localization of proliferating cell nuclear antigen (PCNA) were used to identify the proliferative zone(s). Cellular migration patterns were determined through the use of the thymidine analog 5-bromo-2-deoxyuridine (BrdU) over a 24-, 48-, and 72-hr period. Apoptotic nuclei were identified utilizing terminal deoxynucleotidyl transferase d-UTP nick-end labeling (TUNEL). Both cecum and the initial portion of the proximal colon (P1) exhibited a proliferative zone at or near the crypt base, and migration proceeded upwards toward the surface epithelium lining the intestinal lumen, where apoptosis occurred Turnover time of crypt columnar cells was determined to be about 3 days; that of mucous cells was estimated to be about 5 weeks. Rabbit cecum and proximal colon P1 are similar in their cellular morphology and epithelial cell kinetics. In both, the major proliferative zone is located at or near the crypt base, from which crypt columnar cells migrate toward the lumenal surface epithelium over a period of 3 days. Goblet cell turnover rate is much slower than that of columnar cells.
Anat Rec 2001 12 01
PMID:Epithelial cell dynamics in rabbit cecum and proximal colon P1. 1174 97

Outgrowth and branching of solid cords are the initial events in postnatal prostatic morphogenesis. These processes involve cell proliferation and their projection into the stroma and precede epithelial canalization. The purpose of the present study was to examine the dynamics of the prostate epithelium during canalization of the rat ventral prostate in the first week of postnatal development using histological, stereological, and ultrastructural analyses. The terminal deoxynucleotidyltransferase [TdT]-mediated deoxy-UTP nick end labeling assay was used to investigate the occurrence of DNA fragmentation. Our results demonstrate that canalization of the prostate epithelium starts as early as on day 1 (24 hr after birth) and progresses thereafter. By the end of the first week (day 6), luminal volume density reached approximately 3% (P < 0.05) of the organ. Canalization was the result of epithelial cell differentiation and apoptosis. The former involved organization of the epithelial cells into a single layer sitting on the basement membrane, polarization, enlargement of secretory organelles and accumulation of secretory vesicles, microvilli formation, and establishment of the adult pattern of cell junctions. The latter was observed to occur mostly to epithelial cells not in contact with the basement membrane. Structures of variable electron density were observed in the developing lumen. In conclusion, different phenomena seem to be involved in the canalization of the rat ventral prostate. However, it was evident from the present results that complex epithelial cell fate decisions take place during this process.
Anat Rec (Hoboken) 2007 Oct
PMID:Dynamics of the epithelium during canalization of the rat ventral prostate. 1784 55