{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,21]],"date-time":"2026-02-21T02:52:24Z","timestamp":1771642344404,"version":"3.50.1"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"2","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1984,4,15]]},"abstract":"<jats:p>Evidence is available to suggest that Ca2+-calmodulin and cyclic nucleotides are involved in the regulation of ion transport in rabbit ileum. Since both Ca2+-calmodulin and cyclic nucleotides exert many of their effects by phosphorylation, the effects of Ca2+-calmodulin and cyclic nucleotides on phosphorylation of purified microvillus membrane from rabbit ileal mucosa were evaluated. Ca2+-calmodulin increased phosphorylation of five microvillus-membrane peptides, with Mr values of 137000, 77000, 58000, 53000 and 50000. The increases in phosphorylation caused by Ca2+-calmodulin were: Mr-137000 peptide, 111 +\/- 26%; Mr-77000 peptide, 71 +\/- 17%; Mr-58000 peptide, 51 +\/- 8%; Mr-53000 peptide, 113 +\/- 20%. These increases were maximal at 1 microM-calmodulin and 0.3-0.9 microM free Ca2+; concentrations of Ca2+ causing half-maximal effects on phosphorylation for the different peptides were 0.06-0.12 microM. Cyclic AMP and cyclic GMP increased phosphorylation of two peptides, of Mr 137000 and 85000. The concentrations of cyclic nucleotides giving half-maximal phosphorylation of the Mr-137000 peptide were 0.3 microM-cyclic AMP and 4.6 microM-cyclic GMP, and for the Mr-85000 peptide, 3.9 microM-cyclic AMP and 0.05 microM-cyclic GMP. The maximal increase in phosphorylation of the Mr-137000 peptide was 200% for cyclic AMP and 95% for cyclic GMP, and that of the Mr-85000 peptide was 220% for cyclic AMP and 120% for cyclic GMP. These studies demonstrate the existence of Ca2+-calmodulin-, cyclic AMP- and cyclic GMP-dependent protein kinases and substrate proteins in purified rabbit ileal microvillus membranes and that Ca2+ can regulate phosphorylation of these proteins over the presumed physiological concentration range of cytosol free Ca2+.<\/jats:p>","DOI":"10.1042\/bj2190573","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T20:41:29Z","timestamp":1439239289000},"page":"573-581","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Ca2+-calmodulin-, cyclic AMP- and cyclic GMP-induced phosphorylation of proteins in purified microvillus membranes of rabbit ileum"],"prefix":"10.1042","volume":"219","author":[{"given":"M","family":"Donowitz","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M E","family":"Cohen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R","family":"Gudewich","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"L","family":"Taylor","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"G W G","family":"Sharp","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/219\/2\/573\/581623\/bj2190573.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/219\/2\/573\/581623\/bj2190573.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,25]],"date-time":"2021-11-25T13:22:44Z","timestamp":1637846564000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/219\/2\/573\/15169\/Ca2-calmodulin-cyclic-AMP-and-cyclic-GMP-induced"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1984,4,15]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1984,4,15]]}},"URL":"https:\/\/doi.org\/10.1042\/bj2190573","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1984,4,15]]}}}