Identification of a novel protein containing two C2 domains selectively expressed in the rat brain and kidney.
We have isolated and characterized a rat brain cDNA clone which encodes a new protein of 474 amino acids in length which contains two C2 domains structurally homologous to those present in synaptotagmins. The overall amino acid identity in C2 domains between this protein and the synaptotagmins is 36-44%. This protein also contains 3 putative consensus sequences for phosphorylation by cAMP-dependent protein kinase. RNA blot hybridization revealed a 3.0 kb transcript abundantly expressed only in the rat brain and the kidney. Thus, we called this brain/kidney protein (B/K). In situ hybridization and Northern blot analyses showed that the B/K transcript was found in forebrain including the olfactory bulb, cerebral cortex, hippocampus, and hypothalamus. In the kidney, high levels of B/K transcript were expressed in the papillary region of the inner medulla, the inner stripe of the outer medulla and the cortex. The selective expression in forebrain and kidney suggests that B/K may be involved in similar cAMP-dependent processes at these very different sites.
Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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Kwon
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Gainer
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Wray
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Chin
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism*; D002135:Calcium-Binding Proteins; D016384:Consensus Sequence; D000242:Cyclic AMP / Q000494:pharmacology; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification; D015870:Gene Expression; D017403:In Situ Hybridization; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000737:chemistry; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D011506:Proteins / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017385:Sequence Homology; D050857:Synaptotagmins; D014018:Tissue Distribution
D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D011506:Proteins; D012333:RNA, Messenger; D050857:Synaptotagmins; D000242:Cyclic AMP; D011494:Protein Kinases