scholarly journals The tubB alpha-tubulin gene is essential for sexual development in Aspergillus nidulans.

1991 ◽  
Vol 5 (11) ◽  
pp. 2014-2023 ◽  
Author(s):  
K E Kirk ◽  
N R Morris
Keyword(s):  
Aspergillus Nidulans ◽  
Sexual Development ◽  
Tubulin Gene ◽  
Alpha Tubulin

Either alpha-tubulin isogene product is sufficient for microtubule function during all stages of growth and differentiation in Aspergillus nidulans

1993 ◽  
Vol 13 (8) ◽  
pp. 4465-4476
Author(s):  
K E Kirk ◽  
N R Morris
Keyword(s):  
Aspergillus Nidulans ◽  
Sexual Development ◽  
Vegetative Growth ◽  
Nuclear Migration ◽  
Inducible Promoter ◽  
Coding Region ◽  
Alpha Tubulin ◽  
Tubulin Isotype ◽  
Genes Encoding ◽  
Microtubule Function

The filamentous fungus Aspergillus nidulans has two genes encoding alpha-tubulin, tubA and tubB, which are differentially required at distinct stages during the life cycle. The tubA gene is required during vegetative growth for mitosis and nuclear migration (B. R. Oakley, C. E. Oakley, and J. E. Rinehart, Mol. Gen. Genet. 208:135-144, 1987; P. Doshi, C. A. Bossie, J. H. Doonan, G. S. May, and N. R. Morris, Mol. Gen. Genet. 225:129-141, 1991). The tubB gene is not required for any detectable aspect of vegetative growth or asexual reproduction but is essential during sexual development prior to the first meiotic division (K. E. Kirk and N. R. Morris, Genes Dev. 5:2014-2023, 1991). In this study, we determined whether the role of each alpha-tubulin gene is to provide a specific isotype necessary for a particular microtubule function or whether either alpha-tubulin isotype, if present in sufficient quantities, can participate effectively in all types of microtubule. Strains carrying a deletion allele of tubB (tubB delta) produce no ascospores from a cross. When one copy of a plasmid containing the region upstream of the tubB gene fused to the tubA coding region was integrated into a tubB delta strain, ascosporogenesis proceeded beyond the tubB delta block and resulted in the formation of sexual spores. However, irregular numbers of spores formed in some asci during development, and the ascospores had greatly diminished viability and aberrant morphologies. These defects were nearly corrected when two additional copies of the tubA coding region were integrated into the tubB delta strain. These results indicate that the tubA alpha-tubulin isotype can form functional microtubules during sexual development in the absence of tubB protein. In a reciprocal set of experiments, we examined whether upregulation of tubB can complement the tubA4 mutation, which causes supersensitivity to benomyl during vegetative growth. When tubA4 strains integrated a plasmid containing an alcohol-inducible promoter joined to the tubB coding region and subsequently overexpressed the tubB isotype, the benomyl supersensitivity normally caused by the tubA4 allele was relieved. These results indicate that when enough tubB alpha-tubulin is supplied, strains lacking functional tubA isotype can still form microtubules which effectively carry out mitosis and nuclear migration.

scholarly journals Either alpha-tubulin isogene product is sufficient for microtubule function during all stages of growth and differentiation in Aspergillus nidulans.

1993 ◽  
Vol 13 (8) ◽  
pp. 4465-4476 ◽  
Author(s):  
K E Kirk ◽  
N R Morris
Keyword(s):  
Aspergillus Nidulans ◽  
Sexual Development ◽  
Vegetative Growth ◽  
Nuclear Migration ◽  
Inducible Promoter ◽  
Coding Region ◽  
Alpha Tubulin ◽  
Tubulin Isotype ◽  
Genes Encoding ◽  
Microtubule Function

The filamentous fungus Aspergillus nidulans has two genes encoding alpha-tubulin, tubA and tubB, which are differentially required at distinct stages during the life cycle. The tubA gene is required during vegetative growth for mitosis and nuclear migration (B. R. Oakley, C. E. Oakley, and J. E. Rinehart, Mol. Gen. Genet. 208:135-144, 1987; P. Doshi, C. A. Bossie, J. H. Doonan, G. S. May, and N. R. Morris, Mol. Gen. Genet. 225:129-141, 1991). The tubB gene is not required for any detectable aspect of vegetative growth or asexual reproduction but is essential during sexual development prior to the first meiotic division (K. E. Kirk and N. R. Morris, Genes Dev. 5:2014-2023, 1991). In this study, we determined whether the role of each alpha-tubulin gene is to provide a specific isotype necessary for a particular microtubule function or whether either alpha-tubulin isotype, if present in sufficient quantities, can participate effectively in all types of microtubule. Strains carrying a deletion allele of tubB (tubB delta) produce no ascospores from a cross. When one copy of a plasmid containing the region upstream of the tubB gene fused to the tubA coding region was integrated into a tubB delta strain, ascosporogenesis proceeded beyond the tubB delta block and resulted in the formation of sexual spores. However, irregular numbers of spores formed in some asci during development, and the ascospores had greatly diminished viability and aberrant morphologies. These defects were nearly corrected when two additional copies of the tubA coding region were integrated into the tubB delta strain. These results indicate that the tubA alpha-tubulin isotype can form functional microtubules during sexual development in the absence of tubB protein. In a reciprocal set of experiments, we examined whether upregulation of tubB can complement the tubA4 mutation, which causes supersensitivity to benomyl during vegetative growth. When tubA4 strains integrated a plasmid containing an alcohol-inducible promoter joined to the tubB coding region and subsequently overexpressed the tubB isotype, the benomyl supersensitivity normally caused by the tubA4 allele was relieved. These results indicate that when enough tubB alpha-tubulin is supplied, strains lacking functional tubA isotype can still form microtubules which effectively carry out mitosis and nuclear migration.

A mutation in the alpha 1-tubulin gene of Chlamydomonas reinhardtii confers resistance to anti-microtubule herbicides

1993 ◽  
Vol 106 (1) ◽  
pp. 209-218 ◽  
Author(s):  
S.W. James ◽  
C.D. Silflow ◽  
P. Stroom ◽  
P.A. Lefebvre
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Resistance Mutation ◽  
In Vitro Translation ◽  
Predicted Amino Acid Sequence ◽  
Two Dimensional ◽  
Wild Type ◽  
Tubulin Gene ◽  
Alpha Tubulin ◽  
Tubulin Genes

A mutation in the alpha 1-tubulin gene of Chlamydomonas reinhardtii was isolated by using the amiprophos-methyl-resistant mutation apm1-18 as a background to select new mutants that showed increased resistance to the drug. The upA12 mutation caused twofold resistance to amiprophos-methyl and oryzalin, and twofold hypersensitivity to the microtubule-stabilizing drug taxol, suggesting that the mutation enhanced microtubule stability. The resistance mutation was semi-dominant and mapped to the same interval on linkage group III as the alpha 1-tubulin gene. Two-dimensional gel immunoblots of proteins in the mutant cells revealed two electrophoretically altered alpha-tubulin isoforms, one of which was acetylated and incorporated into microtubules in the axoneme. The mutant isoforms co-segregated with the drug-resistance phenotypes when mutant upA12 was backcrossed to wild-type cells. Two-dimensional gel analysis of in vitro translation products showed that the non-acetylated variant alpha-tubulin was a primary gene product. DNA sequence analysis of the alpha 1-tubulin genes from mutant and wild-type cells revealed a single missense mutation, which predicted a change in codon 24 from tyrosine in wild type to histidine in mutant upA12. This alteration in the predicted amino acid sequence corroborated the approximately +1 basic charge shift observed for the variant alpha-tubulins. The mutant allele of the alpha 1-tubulin gene was designated tua1-1.

Expression of alpha- and beta-tubulin genes during dimorphic-phase transitions of Histoplasma capsulatum

1989 ◽  
Vol 9 (5) ◽  
pp. 2042-2049
Author(s):  
G S Harris ◽  
E J Keath ◽  
J Medoff
Keyword(s):  
Phase Transitions ◽  
Histoplasma Capsulatum ◽  
Blot Hybridization ◽  
Dot Blot ◽  
Dimorphic Fungus ◽  
Tubulin Gene ◽  
Beta Tubulin ◽  
Two Dimensional Gel Electrophoresis ◽  
Western Blots ◽  
Alpha Tubulin

Recent investigations have confirmed the presence of one alpha-tubulin gene (TUB1) and one beta-tubulin gene (TUB2) in the dimorphic fungus Histoplasma capsulatum. In the present study, Northern blot (RNA blot) analyses revealed multiple alpha-tubulin transcripts and a single beta-tubulin transcript in the yeast and mycelial phases of the high-virulence 217B strain and low-virulence Downs strain. S1 nuclease protection assays demonstrated one initiation start site and two major stop sites for the TUB1 transcripts, suggesting that variations in 3' processing generate the alpha-tubulin messages of 2.5 and 2.0 kilobases. Dot blot hybridization experiments indicated that tubulin gene expression is developmentally regulated during the dimorphic phase transitions. alpha- and beta-tubulin mRNAs increased six- to eightfold during the yeast-to-mycelium conversion and decreased two- to threefold during the reverse transition. These changes in tubulin mRNA content coincided with major morphological events associated with H. capsulatum development. Western blots (immunoblots) of H. capsulatum yeast-specific proteins resolved by two-dimensional gel electrophoresis demonstrated a single alpha- and a single beta-tubulin isoform. Multiple tubulin polypeptides expressed in mycelia are probably products of posttranslational modifications.

scholarly journals Interacting proteins identified by genetic interactions: a missense mutation in alpha-tubulin fails to complement alleles of the testis-specific beta-tubulin gene of Drosophila melanogaster.

1989 ◽  
Vol 9 (3) ◽  
pp. 875-884 ◽  
Author(s):  
T S Hays ◽  
R Deuring ◽  
B Robertson ◽  
M Prout ◽  
M T Fuller
Keyword(s):  
Drosophila Melanogaster ◽  
Missense Mutation ◽  
Null Allele ◽  
Genetic Interaction ◽  
Structural Proteins ◽  
Interacting Proteins ◽  
Tubulin Gene ◽  
Beta Tubulin ◽  
Gene Encoding ◽  
Alpha Tubulin

In this paper we demonstrate that failure to complement between mutations at separate loci can be used to identify genes that encode interacting structural proteins. A mutation (nc33) identified because it failed to complement mutant alleles of the gene encoding the testis-specific beta 2-tubulin of Drosophila melanogaster (B2t) did not map to the B2t locus. We show that this second-site noncomplementing mutation is a missense mutation in alpha-tubulin that results in substitution of methionine in place of valine at amino acid 177. Because alpha- and beta-tubulin form a heterodimer, our results suggest that the genetic interaction, failure to complement, is based on the structural interaction between the protein products of the two genes. Although the nc33 mutation failed to complement a null allele of B2t (B2tn), a deletion of the alpha-tubulin gene to which nc33 mapped complemented B2tn. Thus, the failure to complement appears to require the presence of the altered alpha-tubulin encoded by the nc33 allele, which may act as a structural poison when incorporated into either the tubulin heterodimer or microtubules.

Interacting proteins identified by genetic interactions: a missense mutation in alpha-tubulin fails to complement alleles of the testis-specific beta-tubulin gene of Drosophila melanogaster

1989 ◽  
Vol 9 (3) ◽  
pp. 875-884
Author(s):  
T S Hays ◽  
R Deuring ◽  
B Robertson ◽  
M Prout ◽  
M T Fuller
Keyword(s):  
Drosophila Melanogaster ◽  
Missense Mutation ◽  
Null Allele ◽  
Genetic Interaction ◽  
Structural Proteins ◽  
Interacting Proteins ◽  
Tubulin Gene ◽  
Beta Tubulin ◽  
Gene Encoding ◽  
Alpha Tubulin

In this paper we demonstrate that failure to complement between mutations at separate loci can be used to identify genes that encode interacting structural proteins. A mutation (nc33) identified because it failed to complement mutant alleles of the gene encoding the testis-specific beta 2-tubulin of Drosophila melanogaster (B2t) did not map to the B2t locus. We show that this second-site noncomplementing mutation is a missense mutation in alpha-tubulin that results in substitution of methionine in place of valine at amino acid 177. Because alpha- and beta-tubulin form a heterodimer, our results suggest that the genetic interaction, failure to complement, is based on the structural interaction between the protein products of the two genes. Although the nc33 mutation failed to complement a null allele of B2t (B2tn), a deletion of the alpha-tubulin gene to which nc33 mapped complemented B2tn. Thus, the failure to complement appears to require the presence of the altered alpha-tubulin encoded by the nc33 allele, which may act as a structural poison when incorporated into either the tubulin heterodimer or microtubules.

Morphogenesis and alpha-tubulin gene of plasmodium in Didymium megalosporum

2014 ◽  
Vol 196 (5) ◽  
pp. 369-374 ◽  
Author(s):  
Xiaoxia Song ◽  
Huacheng Zhong ◽  
Qi Wang ◽  
Yu Li
Keyword(s):  
Tubulin Gene ◽  
Alpha Tubulin

scholarly journals Preferential expression of an alpha-tubulin gene of Arabidopsis in pollen.

1992 ◽  
Vol 4 (5) ◽  
pp. 557-571 ◽  
Author(s):  
J L Carpenter ◽  
S E Ploense ◽  
D P Snustad ◽  
C D Silflow
Keyword(s):  
Tubulin Gene ◽  
Alpha Tubulin ◽  
Preferential Expression
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