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

To identify factors that directly regulate the synthesis and secretion of atrial natriuretic peptide (ANP) in neuronal cells, we have developed a neuron-enriched primary culture system from fetal rat brains. A number of factors proved of importance in maintaining adequate levels of ANP secretion in such cultures: 1) cultures derived from diencephalon produced much more ANP than cultures derived from diencephalon produced with the distribution of ANP-containing cells in the rat brain; 2) brains from rats at gestational day 17 proved a better source of ANP-secreting cells than brains from rats at gestational day 16; 3) the presence of serum was required in the latter stages of the culture period to allow expression of the ANP gene; and 4) the cultures secreted more ANP when maintained at 39 C vs. 37 C. ANP mRNA transcripts in the neuron-enriched primary cultures were analyzed by S1 nuclease protection and shown to have a transcription start site similar to that employed by rat atrium and fetal hypothalamus in vivo. Dexamethasone and T3, in contrast to their stimulatory effect on ANP production in cardiocyte cultures, suppressed both the release of immunoreactive ANP and the levels of ANP mRNA in the neuron-enriched primary cultures. The cultures incorporated [35S]cysteine into immunoprecipitable ANP. HPLC analysis of 35S-labeled products in the medium revealed that, unlike neonatal cardiocyte cultures, the majority of secreted immunoreactive ANP migrated with the processed form(s) of ANP rather than the prohormone.
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PMID:Production and differential endocrine regulation of atrial natriuretic peptide in neuron-enriched primary cultures. 170 3

The structure and expression of the distal part of the malK-lamB operon in Escherichia coli was studied. DNA sequencing was performed as far as a HinfI restriction site located 1313 base-pairs downstream from gene lamB. The open reading frame, formerly called molA, which begins 245 base-pairs downstream from gene lamB, is longer than was initially thought, and was renamed malM. It could encode a protein of 306 amino acid residues. The complete malM open reading frame was cloned under control of the tac 12 promoter. In maxicells, the resulting plasmid permitted tac12-promoted synthesis of two polypeptides, encoded by gene malM, with apparent molecular weights of 37 X 10(3) and 34.5 X 10(3). We provide strong evidence that the 34.5 X 10(3) Mr protein is derived from the 37 X 10(3) Mr protein by processing at the amino-terminal end, and that this processed form is located in the periplasmic space. We show that the chromosomal malM gene is expressed as part of the malK-lamB operon, and that its product is periplasmic. Finally, we demonstrate with nuclease S1 mapping experiments that the mRNA terminates at a typical rho-independent terminator located about 45 base-pairs beyond the end of gene malM, which is thus the last gene of the malK-lamB operon.
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PMID:malM, a new gene of the maltose regulon in Escherichia coli K12. I. malM is the last gene of the malK-lamB operon and encodes a periplasmic protein. 243 55