Maternally expressed and partially redundant beta-tubulins in Caenorhabditis elegans are autoregulated.
J Cell Sci
; 117(Pt 3): 457-64, 2004 Jan 26.
Article
em En
| MEDLINE
| ID: mdl-14702387
ABSTRACT
The mitotic spindle, which partitions replicated chromosomes to daughter cells during cell division, is composed of microtubule assemblies of alpha/beta-tubulin heterodimers. Positioning of the mitotic spindle influences the size and location of daughter cells, and can be important for the proper partitioning of developmental determinants. We describe two semi-dominant mis-sense mutations in tbb-2, one of two C. elegans beta-tubulin genes that are maternally expressed and together are required for microtubule-dependent processes in the early embryo. These mutations result in a posteriorly displaced and misoriented mitotic spindle during the first cell division. In contrast, a probable tbb-2 null allele is recessive, and when homozygous results in less severe spindle positioning defects and only partially penetrant embryonic lethality. Two of the tbb-2 mutations result in reduced levels of TBB-2 protein, and increased levels of a second maternally expressed beta-tubulin, TBB-1. However, levels of TBB-1 are not increased in a tbb-2 mutant with an allele that does not result in reduced levels of TBB-2 protein. We conclude that feedback regulation influences maternal beta-tubulin expression in C. elegans, but cannot fully restore normal microtubule function in the absence of one beta-tubulin isoform.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tubulina (Proteína)
/
Caenorhabditis elegans
/
Microtúbulos
/
Fuso Acromático
Limite:
Animals
Idioma:
En
Revista:
J Cell Sci
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Estados Unidos