TY - JOUR
T1 - Cloning and characterization of a divergent α-tubulin that is expressed specifically in dividing amebae of Naegleria gruberi
AU - Chung, Sunglan
AU - Cho, Jaeyoung
AU - Cheon, Hyeonjoo
AU - Paik, Soonyoung
AU - Lee, Joohun
N1 - Funding Information:
This work was supported by a grant from KOSEF (1999-2-207-003-3) to J. Lee.
PY - 2002/6/26
Y1 - 2002/6/26
N2 - A novel α-tubulin gene (α6) was cloned from a genomic library of Naegleria gruberi strain NB-1 and characterized. The open reading frame of α6 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 α6 showed considerable divergence (68.4% identity) when compared with previously cloned N. gruberi α-tubulin genes, which share about 97% identity in DNA sequences. The deduced aa sequence of α6-tubulin was 61.9% identical to that of α13-tubulin, which was cloned from the same strain, and showed similar identities to those of α-tubulins from other species (54∼62%). These data showed that α6-tubulin is one of the most divergent α-tubulins so far known. α6-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 α6-tubulin showed that α6-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 α-tubulin that is specifically utilized for spindle-fiber microtubules and distinct from the flagellar axonemal α-tubulins in N. gruberi, hence confirmed the multi-tubulin hypothesis in this organism.
AB - A novel α-tubulin gene (α6) was cloned from a genomic library of Naegleria gruberi strain NB-1 and characterized. The open reading frame of α6 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 α6 showed considerable divergence (68.4% identity) when compared with previously cloned N. gruberi α-tubulin genes, which share about 97% identity in DNA sequences. The deduced aa sequence of α6-tubulin was 61.9% identical to that of α13-tubulin, which was cloned from the same strain, and showed similar identities to those of α-tubulins from other species (54∼62%). These data showed that α6-tubulin is one of the most divergent α-tubulins so far known. α6-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 α6-tubulin showed that α6-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 α-tubulin that is specifically utilized for spindle-fiber microtubules and distinct from the flagellar axonemal α-tubulins in N. gruberi, hence confirmed the multi-tubulin hypothesis in this organism.
UR - http://www.scopus.com/inward/record.url?scp=0037178262&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0037178262&partnerID=8YFLogxK
U2 - 10.1016/S0378-1119(02)00509-7
DO - 10.1016/S0378-1119(02)00509-7
M3 - Article
C2 - 12137945
AN - SCOPUS:0037178262
VL - 293
SP - 77
EP - 86
JO - Gene
JF - Gene
SN - 0378-1119
IS - 1-2
ER -