Cloning and characterization of a divergent alpha-tubulin that is expressed specifically in dividing amebae of Naegleria gruberi.
Gene
; 293(1-2): 77-86, 2002 Jun 26.
Article
em En
| MEDLINE
| ID: mdl-12137945
ABSTRACT
A novel alpha-tubulin gene (alpha6) was cloned from a genomic library of Naegleria gruberi strain NB-1 and characterized. The open reading frame of alpha6 contained 1359 nucleotides encoding a protein of 452 amino acids (aa) with a calculated molecular weight of 50.5 kDa. The nucleotide sequence of the open reading frame of alpha6 showed considerable divergence (68.4% identity) when compared with previously cloned N. gruberi alpha-tubulin genes, which share about 97% identity in DNA sequences. The deduced aa sequence of alpha6-tubulin was 61.9% identical to that of alpha13-tubulin, which was cloned from the same strain, and showed similar identities to those of alpha-tubulins from other species (54 approximately 62%). These data showed that alpha6-tubulin is one of the most divergent alpha-tubulins so far known. Alpha6-tubulin was found to be expressed in actively growing cells and repressed quickly when these cells were induced to differentiate. Immunostaining with an antibody against alpha6-tubulin showed that alpha6-tubulin is present in the nuclei and mitotic spindle-fibers but absent in flagellar axonemes or cytoskeletal microtubules. These data finally established the presence of an alpha-tubulin that is specifically utilized for spindle-fiber microtubules and distinct from the flagellar axonemal alpha-tubulins in N. gruberi, hence confirmed the multi-tubulin hypothesis in this organism.
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Base de dados:
MEDLINE
Assunto principal:
Tubulina (Proteína)
/
Naegleria
Limite:
Animals
Idioma:
En
Revista:
Gene
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Coréia do Sul