Isolation of different brain-specific isotypes of alpha-tubulins from chum salmon (Oncorhynchus keta).

An alpha-tubulin cDNA clone, pTUB5 (1496 bp), encoding a protein of 444 amino acids (mol. wt. 48,840), has been isolated from the brain of Pacific salmon, Oncorhynchus keta. Partial sequence data were also obtained for two other alpha-tubulin isotypes, pTUB6 and pTUB9, which are similar in sequence to pTUB5 except in the carboxy region of the protein. This region of alpha-tubulin has previously been shown to be important for the binding of microtubule associated proteins suggesting that the isotypes described in this study may represent differentially controlled elements of the neural tubulin population. The isotypes show brain-specific expression and are the first tubulins to be reported for this tissue in fish.