A novel member of the dynamin family of GTP-binding proteins is expressed specifically in the testis

Abstract

Dynamin is a member of a new GTPase family, which includes the mouse Mx protein, the yeast VPS1 and the Drosophila shibire gene product. A high homology with the shibire product suggests a role for dynamin in the endocytotic process, but it is expressed only in mature neurons. We identified two additional dynamin-like pro-teins in rats, by using the polymerase chain reaction with degenerate primers corresponding to the GTP-binding areas conserved between dynamin and VPS1. The full coding sequence of one of them, dynamin-2, revealed that it has 848 amino acids and has great sim-ilarity with brain dynamin and the shibire product. Northern blot analysis and in situ hybridization revealed its expression to be specific to the seminiferous tubules in the testis. Dynamin-2 (testis type dynamin) was expressed in germ-cell-depleted testis as well, indi-cating its expression in Sertoli cells. Our data imply that a number of dynamin family proteins, which are prod-ucts of distinct genes, may play different roles specific to each cell type in the same rat.