ALTERNATIVE SPLICING AND TISSUE-SPECIFIC EXPRESSION OF THE 5'-TRUNCATED BCCE-1 VARIANT BCCE-1-DELTA(514)

In man, non-excitable as well as electrically excitable cells, depleti on of intracellular Ca2+ stores after stimulation of G protein coupled receptors or receptor tyrosine kinases is followed by Ca2+ entry acro ss the plasma membrane, a mechanism referred to as capacitative calciu m entry (CCE) [Putney, J.W., Cell Calcium 11 (1990) 611-624; Fasolato, C, et al., Trends Pharmacol Sci, 15 (1993) 77-83], Recently, me repor ted that bCCE 1, a homologue of the Drosophila protein tip, exhibits t he characteristics of CCE channels [Philipp, S, et al., EMBO J. 15 (19 96) 6166-6171]. In this study, we report the cloning of a 5' truncated splice variant (bCCE 1 Delta(514)) of the full-length bCCE 1, The bCC E 1 Delta(514) cDNA encodes a protein of 486 amino acids with the ATG triplet encoding M-514 of bCCE 1 as translation initiation codon and, therefore, comprises two putative transmembrane segments corresponding to the predicted transmembrane segments 5 and 6 of bCCE 1. bCCE 1 Del ta(514) transcripts appear to be specifically expressed in the adrenal gland and genome analysis reveals an alternative splice site within a n exon of the CCE 1 gene leading to the formation of bCCE 1 Delta(514) . (C) 1998 Federation of European Biochemical Societies.