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)

A cytochemical technique for the electron microscopic localization of calcium adenosine triphosphatase (Ca-ATPase) was utilized to localize this enzyme in the enterocytes of rachitic and vitamin D-replete chicks. In animals treated with cholecalciferol (CC, vitamin D3), an electron-dense reaction product was located along the basolateral membranes of the absorptive cells within 72 hr after injection. Similarly, a reaction product was identified in association with the basolateral membranes within 24 hr after injection of 1,25-dihydroxycholecalciferol, the active metabolite of vitamin D. A microvillar reaction product was not seen in either of these two groups. Electron-dense reaction products were also seen in association with mitochondria and scattered throughout the cytoplasm of these enterocytes. The Ca-ATPase reaction product was dependent upon the presence of medium calcium and substrate (ATP), was inhibited by vanadate, and was heat labile. In the rachitic animals, a reaction product indicative of Ca-ATPase activity was not seen in association with either the basolateral membranes or the mitochondria. These data appear to indicate that an energy-requiring calcium-activated membrane pump plays a role in the flux of calcium across the enterocytes of the small intestine.
Anat Rec 1987 Dec
PMID:Electron microscopic cytochemical localization of a basolateral calcium adenosine triphosphatase in vitamin D replete chick enterocytes. 283 84

A three-dimensional reconstruction of high endothelial venules (HE-venules) of an entire mouse lymph node is presented. The reconstruction has been made by means of the histochemical technique for alpha-naphthylacetate esterase. The course of the HE-venules is shown in coherence with lymphocytic aggregates (follicles and unit), which were concomitantly reconstructed. Carbonic anhydrase, glutamate-, and alpha-glycerophosphate dehydrogenase were found in the high endothelia, while calcium-stimulated NA+, K+ ATP-ase and the acetylcholinesterase were localized to the endothelia and/or to the perivascular sheath of the HE-venules and submarginal capillaries.
Anat Rec 1985 Aug
PMID:A three-dimensional reconstruction of high endothelial venules in the mouse lymph node: an enzyme-histochemical study. 293 5

Transmission electron microscopy and ultracytochemistry were employed in an attempt to localize the enzyme calcium adenosine triphosphatase (Ca-ATPase) in the rod outer segments (ROS) of the toad retina. Utilizing a one-step incubation procedure, Ca-ATPase was identified as an electron-dense precipitate in the intradiskal spaces of the rod disks (vesicles) of the ROS. Analytical microscopy identified the reaction product as lead phosphate. The formation of the reaction product was dependent on the presence of ATP (the substrate) and calcium ions. However, calcium ions could be substituted for by magnesium ions. In addition, the reaction was vanadate sensitive. The latter is known to inhibit Ca-ATPase activity. Such data appear to indicate the presence of a Ca-Mg-ATPase in association with the rod disks. Since cyclic guanosine monophosphate (cyclic GMP), rather than calcium ions, is currently believed to be the primary intracellular messenger associated with phototransduction, the presence of an ROS Ca-ATPase may indicate other functions for this cation in the physiology and biochemistry of the visual process. Ca-ATPase might play a role in directional calcium fluxes between intracellular compartments.
Anat Rec 1988 Jul
PMID:Electron microscopic cytochemical localization of Ca-ATPase in the rod outer segments of the toad Bufo marinus. 297 64

ATP-dependent DNAase genes of Bac. subtilis were originally cloned in E. coli plasmid pBR322. These genes are expressed in rec BC mutant E. coli cells leading to a complete recovery of the enzyme activity. Bac. subtilis enzyme suppresses reparative properties of the rec BC mutant to a considerable extent but is unable to replace functionally the E. coli mutant enzyme in recombination process.
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PMID:[Partial suppression of rec B rec C mutations in E. coli by plasmid pBR 322 containing a Bacillus subtilis chromosome insertion]. 298 61

We have identified in Bacillus subtilis an analogue of the Escherichia coli RecA protein. Its activities suggest that it has a corresponding role in general genetic recombination and in regulation of SOS (DNA repair) functions. The B. subtilis protein (B. subtilis Rec) has a Mr of 42,000 and cross-reacts with antisera raised against E. coli RecA protein. Its level is significantly reduced in the recombination-deficient recE4 mutant. B. subtilis Rec is induced 10- to 20-fold in rec+ strains following treatment with mitomycin C, whereas it is not induced in the recombination-deficient mutants recE4, recE45, and recA1. We have purified B. subtilis Rec about 2000-fold to near homogeneity and we describe its activities. It catalyzes DNA-dependent hydrolysis of dATP at a rate comparable to that of E. coli RecA protein. However, B. subtilis Rec has a negligible ATPase activity, although ATP effectively inhibits dATP hydrolysis. In the presence of dATP, B. subtilis Rec catalyzes DNA strand transfer, assayed by the conversion of phi X174 linear duplex DNA and homologous circular single-stranded DNA to replicative form II (circular double-stranded DNA with a discontinuity in one strand). ATP does not support strand transfer by this protein. B. subtilis Rec catalyzes proteolytic cleavage of E. coli LexA repressor in a reaction that requires single-stranded DNA and nucleoside triphosphate. This result suggests that an SOS regulatory system like the E. coli system is present in B. subtilis. The B. subtilis enzyme does not promote any detectable cleavage of the E. coli bacteriophage lambda repressor.
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PMID:Purification of a RecA protein analogue from Bacillus subtilis. 315 34

Shutoff of respiration is one of a number of recA+ lexA+ dependent (SOS) responses caused by far ultraviolet (245 nm) radiation (UV) damage of DNA in Escherichia coli cells. Thus far no rec/lex response has been shown to require the recB recC gene product, the RecBC enzyme. We report in this paper that UV-induced respiration shutoff did not occur in either of these radiation-sensitive derivatives of K12 strain AB1157 nor in the recB recC double mutant. The sbcB gene product is exonuclease I and it has been reported that the triple mutant strain recB recC sbcB has near normal recombination efficiency and resistance to UV. The sbcB strain shut off its respiration after UV but the triple mutant did not show UV-induced respiration shutoff; the shutoff and death responses were uncoupled. We concluded that respiration shutoff requires RecBC enzyme activity. The RecBC enzyme has ATP-dependent double-strand exonuclease activity, helicase activity and several other activities. We tested a recBC+ (double dagger) mutant strain (recC 1010) that had normal recombination efficiency and resistance to UV but which possessed no ATP-dependent double-strand exonuclease activity. This strain did not shut off its respiration. The presence or absence of other RecBC enzyme activities in this mutant is not known. These results support the hypothesis that ATP-dependent double-strand exonuclease activity is necessary for UV-induced respiration shutoff.
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PMID:RecBC enzyme activity is required for far-UV induced respiration shutoff in Escherichia coli K12. 351 Mar 70

All recB(-) and recC(-) mutants of E. coli carry out significant residual genetic recombination, whereas all recA(-) mutants form no recombinants. This observation suggests that an alternative minor pathway of recombination, independent of recB(+) and recC(+) products, may be operative in Escherichia coli. Rec(+) revertants of recB(-)recC(+), recB(+)recC(-), and recB(-) strains of E. coli have been isolated and are shown to fall into at least two major genotypic classes. One class carries revertant mutations which map in or very near the recB and recC genes. In this class an ATP-dependent DNase characteristic of wild type E. coli is restored. The reversions in this class are probably back-mutations or intragenic suppressor mutations. A second class carries revertant mutations which are located far from the recB and recC genes. In this class there is a high level of DNase activity which does not require ATP and is inactive on T4 DNA. Indirect and not informational suppression appears to be responsible for the second class of revertants. The suggestion is made that restoration of recombination by indirect suppression involves an activation or derepression of one or a series of enzymes, which participate in a pathway of recombination, alternative to the recB and recC pathway, but normally of minor importance. The ATP-independent DNase may be one of these enzymes.
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PMID:Biochemical and genetic studies of recombination proficiency in Escherichia coli. II. Rec+ revertants caused by indirect suppression of rec- mutations. 424 56

The inactivation of rec BC nuclease activity and simultaneously the separation of 3 DNA-dependent ATPases and an ATP-independent DNases specific for single-stranded DNA have been observed after DEAE-cellulose chromatography of cell extracts from Escherichia coli. Two of the ATPases catalyze the strand separation of duplex DNA. Reconstitution of ATP-dependent DNase activity has been carried out by the combination of the separated enzymes.
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PMID:Resolution and reconstitution of the rec BC deoxyribonuclease of Escherichia coli. 622 38

The recombination proficiency of three recipient strains of Escherichia coli K12 carrying different plasmids was investigated by conjugal mating with Hfr Cavalli. Some plasmids (e.g. R1drd 19, R6K) caused a marked reduction in the yield of recombinants formed in crosses with Hfr but did not reduce the ability of host strains to accept plasmid F104. The effect of plasmids on recombination was host-dependent. In Hfr crosses with AB1157 (R1-19) used as a recipient the linkage between selected and unselected proximal markers of the donor was sharply decreased. Plasmid R1-19 also decreased the yield of recombinants formed by recF, recL, and recB recC sbcA mutants, showed no effect on the recombination proficiency of recB recC sbcB mutant, and increased the recombination proficiency of recB, recB recC sbcB recF, and recB recC sbcB recL mutants. An ATP-dependent exonuclease activity was found in all tested recB recC mutants carrying plasmid R1-19, while this plasmid did not affect the activity of exonuclease I in strain AB1157 and its rec- derivatives. The same plasmid was also found to protect different rec- derivatives of the strain AB1157 against the lethal action of UV light. We suppose that a new ATP-dependent exonuclease determined by R1-19 plays a role in both repair and recombination of the host through the substitution of or competition with the exoV coded for by the genes recB and recC.
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PMID:Plasmid control of recombination of E. coli K12. 625 17

We studied the formation of linked circular DNA molecules promoted by the combined action of rec 1 protein and type I topoisomerase of Ustilago maydis. When ATP was added as cofactor to reactions containing rec 1 protein, pairs of homologous circular DNA molecules became linked after addition of topoisomerase. Closed circular duplex molecules could be joined at homologous sites with circular single-stranded molecules or with other circular duplex molecules, provided that homologous single-stranded DNA fragments or RNA polymerase and nucleoside triphosphates were also added. Complexes formed were topologically linked through regions of heteroduplex DNA. When the analog adenylyl-imidodiphosphate was substituted for ATP, nonhomologous pairs of circular DNA molecules became linked.
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PMID:Topological linkage of circular DNA molecules promoted by Ustilago rec 1 protein and topoisomerase. 631 15


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