Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cDNA, p1-88, was cloned from a library constructed using rabbit liver mRNA. Sequence analysis indicates that p1-88 is highly similar (congruent to 95%) to the cDNA, p1-8, that encodes rabbit liver cytochrome P-450 1 and that had been isolated from the same library. The predicted amino acid sequence of the protein encoded by p1-88, P-450 IIC4, differs at 25 of 487 amino acids from that encoded by p1-8. P-450 IIC4 was synthesized in vitro using rabbit reticulocyte lysate primed with RNA transcribed from the coding sequence of p1-88 using a bacteriophage T7 RNA polymerase/promoter system. P-450 IIC4 reacts with two monoclonal antibodies that recognize P-450 1 and exhibits the same relative electrophoretic mobility as P-450 1. In contrast, the reactivity of a third monoclonal antibody recognizing P-450 1, 1F11, toward P-450 IIC4 synthesized in vitro is greatly diminished. The latter antibody extensively inhibits hepatic progesterone 21-hydroxylase activity and recognizes phenotypic differences among rabbits in the microsomal concentration of P-450 1. This difference in the immunoreactivity of P-450 IIC4 and P-450 1 with the 1F11 antibody suggests that P-450 IIC4 does not contribute significantly to hepatic progesterone 21-hydroxylase activity. S1 nuclease mapping demonstrates that the expression of mRNAs corresponding to p1-88 are expressed to equivalent extents in rabbits exhibiting high and low expression of mRNAs corresponding to p1-8. Thus, P-450 1 differs from the protein encoded by p1-88, in its regulation, immunoreactivity, and by inference its catalytic properties although the amino acid sequences of P-450 1 and P-450 IIC4 are highly similar (congruent to 95%).
 ...
PMID:Characterization of a second gene product related to rabbit cytochrome P-450 1. 303 48

P-450c21, a cytochrome P-450 enzyme [steroid 21-monooxygenase (steroid 21-hydroxylase), EC 1.14.99.10], mediates the 21-hydroxylation of glucocorticoid and mineralocorticoid hormones in the adrenal gland. The complete sequence of a bovine P-450c21 gene shows it is 3447 base pairs long and contains 10 exons. The intron/exon organization and encoded amino acid sequence indicate that P-450c21 represents a unique family of genes in the P-450 gene superfamily. Primer extension and S1 nuclease protection experiments identified several cap sites for initiation of transcription; the principal cap site produces mRNA with a 5' untranslated region only 11 bases long. S1 nuclease protection experiments confirm that P-450c21 is actively expressed in the adrenal and the testis, an organ not known to secrete 21-hydroxylated steroids.
 ...
PMID:Structure of a bovine gene for P-450c21 (steroid 21-hydroxylase) defines a novel cytochrome P-450 gene family. 348 86

Steroid 21-hydroxylase is expressed at high levels in the adrenal gland, where it is required for the synthesis of mineralocorticoids and glucocorticoids. The cis-acting nucleotide sequences required for expression of murine 21-hydroxylase were assessed by stable transfection of Y1 adrenocortical tumor cells with 21-hydroxylase genes containing progressive deletions of the 5' flanking sequences. Expression of authentic 21-hydroxylase transcripts was quantitated by S1 nuclease protection assays using total RNA from pools of transfectant colonies. Removal of sequences from 1,100 to 230 base pairs preceding the transcription initiation site did not significantly affect 21-hydroxylase transcription. However, an important regulatory element falls between 230 and 180 base pairs upstream of the transcription initiation site. Comparisons of the murine 5' flanking sequence with those of the human and bovine 21-hydroxylase genes revealed a 40-base pair region that is highly conserved among all three species. The conserved sequence in the murine gene occurs between 210 and 170 nucleotides 5' of the transcription initiation site; similar locations are seen in the human and bovine genes. These results thus define an important regulatory region which is required for expression of 21-hydroxylase in Y1 adrenal cells.
 ...
PMID:Characterization of a regulatory region of the steroid 21-hydroxylase gene. 349 Oct 69