Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine the degree of similarity between pituitary and lymphocyte proopiomelanocortin, the lymphocyte mRNA was reverse transcribed, cloned, and sequenced. Murine lymphocyte mRNA was first purified by oligo(dT)-cellulose affinity chromatography and was reverse transcribed by using a selective 3' antisense oligonucleotide primer directed at the boundary between the translated/nontranslated region on the 3' end of exon 3. This cDNA was then amplified in a polymerase chain reaction with selective primers containing Sal I and Kpn I restriction endonuclease sites. Amplified cDNA was then directionally ligated into M13mp18 and M13mp19 bacteriophage and was sequenced. The nucleotide sequence encoding this peptide was identical to that of mouse pituitary corticotropin (ACTH). Elevated levels of lymphocyte immunoreactive ACTH were then induced with bacterial lipopolysaccharide and the peptide(s) was purified by antibody affinity chromatography and reverse-phase high-performance liquid chromatography. The predominant immunoreactive ACTH species was approximately 3 kDa and its sequence was identical to pituitary ACTH(1-25). These results conclusively demonstrate that lymphocytes produce authentic ACTH and harbor its mRNA.
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PMID:Nucleotide and amino acid sequence of lymphocyte-derived corticotropin: endotoxin induction of a truncated peptide. 168 57

Two of four siblings expressed the salt-losing form of congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH) and had identical human lymphocyte antigen (HLA) and complement C4 (fourth component of complement) types (HLA-A3,C4,B35,C4A3,C4BQO,DR1/A2,C-,B18,C4A3, C4BQO,DR6). The father and one unaffected sibling were heterozygous carriers of CAH, as determined by a 30-min iv ACTH stimulation test and HLA typing. In addition, the iv ACTH stimulation test revealed that the mother and the other unaffected sibling also carried an allele for an attenuated form of CAH. Restriction endonuclease digests of genomic DNA obtained from members of this family and from normal unrelated subjects were hybridized with cDNA probes encoding human 21-hydroxylase and C4. With the 21-hydroxylase probe, Southern blots prepared from control DNA samples revealed two major restriction fragments in each of four restriction endonuclease digests; TaqI produced major bands at 3.7 and 3.2 kilobases (kb), KpnI at 4.0 and 2.9 kb, EcoRI at 18 and 13 kb, and BglII at 15 and 12.5 kb. Southern blots prepared from DNA of the two patients lacked the 3.7-kb TaqI and 2.9-kb KpnI fragments, but had increased hybridization intensity (relative to control DNA samples) in the 3.2-kb TaqI and 4.0-kb KpnI fragments. By contrast, blots with EcoRI or BglII had two large hybridization fragments not different from control DNA samples. These data indicate the presence of two different 21-hydroxylase genes. Additional mapping studies revealed that the two genes had the restriction pattern of the inactive 21-hydroxylase gene. When genomic DNA that had been isolated from all members of this family and from normal subjects was hybridized with the human C4 cDNA probe, the restriction fragment hybridization patterns for all four endonuclease digests were similar in the two groups. Hence, our results suggest that the 21-hydroxylase deficiency of our patients is due to conversion of the active 21-hydroxylase gene to the inactive gene. This gene conversion was associated with absence of functional C4B protein, without any detectable alterations in the restriction fragment pattern of the C4 genes.
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PMID:Gene conversion in salt-losing congenital adrenal hyperplasia with absent complement C4B protein. 300 62