par Hascakova-Bartova, Romana;Pouillon, Valérie ;Dewaste, Valérie ;Moreau, Colette ;Jacques, Céline ;Banting, George;Schurmans, Stéphane ;Erneux, Christophe
Référence Biochemical and biophysical research communications, 323, 3, page (920-925)
Publication Publié, 2004-10
Référence Biochemical and biophysical research communications, 323, 3, page (920-925)
Publication Publié, 2004-10
Article révisé par les pairs
Résumé : | Inositol 1,4,5-trisphosphate 3-kinase (IP(3)-3K) catalyses the phosphorylation of inositol 1,4,5-trisphosphate to inositol 1,3,4,5-tetrakisphosphate. cDNAs encoding three mammalian isoforms have been reported and referred to as IP(3)-3KA, IP(3)-3KB, and IP(3)-3KC. IP(3)-3KB is particularly sensitive to proteolysis at the N-terminus, a mechanism known to generate active fragments of lower molecular mass. Endogenous IP(3)-3KB has therefore not been formally identified in tissues. We have probed a series of murine tissues with an antibody directed against the C-terminus of IP(3)-3KB and used IP(3)-3KB deficient mouse tissues as negative controls. IP(3)-3KB was shown to be particularly well expressed in brain, lung, and thymus with molecular masses of 110-120kDa. The identification of the native IP(3)-3KB by Western blotting for the first time will facilitate further studies of regulation of its activity by specific proteases and/or phosphorylation. |