The functional significance of distinct gamma-tubulins in several unrelated eukaryotes remains an enigma due to the difficulties to investigate this question experimentally. Using specific nucleotidic and immunological probes, we have demonstrated that the two divergent @entity238 gamma-tubulins, @entity44073 and @entity44074 , are expressed in cultured cells. @entity44074 is constantly detected at the centrosome and absent in the mitotic spindle, while @entity44073 is extensively recruited to the centrosome during mitosis and relocalizes in the mitotic spindle. The two gamma-tubulins exhibit distinct biochemical properties. @entity44073 is present in the soluble gamma-tubulin small complexes (10S) and gamma-tubulin big complexes (35S) and is loosely associated to the cytoskeleton. In contrast, @entity44074 is undetectable in the soluble fraction and exhibits a tight binding to the centrosome. Syncytial embryos also contain the two gamma-tubulin isotypes, which are differentially recruited at the centrosome. @entity44073 is present in the 10S soluble complexes only, while y-tub37CD is contained in the two soluble complexes and is recruited at the centrosome where it exhibits an heterogeneous binding. These results demonstrated an heterogeneity of the two @entity238 gamma-tubulin isotypes both in the cytoskeletal and the soluble fractions. They suggest the direct implication of the 35S complex in the centrosomal recruitment of gamma-tubulin and a conditional functional redundancy between the two gamma-tubulins.

Differential properties of the two XXXX gamma-tubulin isotypes.

@entity44073 :: ('33501(Tax:7227)', 'Gene') :: ['Gamma-tub23C', 'gamma-tub23C'] @entity238 :: ('7227', 'Species') :: ['Drosophila'] @entity44074 :: ('35199(Tax:7227)', 'Gene') :: ['gamma-tub37CD', 'Gamma-tub37CD']
@entity238 :: (7227,Species) :: ['Drosophila']
