Increased expression of Saccharomyces cerevisiae translation elongation factor 1 alpha bypasses the lethality of a TEF5 null allele encoding elongation factor 1 beta.
Translation elongation factor 1beta (EF-1beta) catalyzes the exchange of bound GDP for GTP on EF-1alpha. The lethality of a null allele of the TEF5 gene encoding EF-1beta in Saccharomyces cerevisiae was suppressed by extra copies of the TEF2 gene encoding EF-1alpha. The strains with tef5::TRP1 suppressed by extra copies of TEF were slow growing, cold sensitive, hypersensitive to inhibitors of translation elongation and showed increased phenotypic suppression of +1 frameshift and UAG nonsense mutations. Nine dominant mutant alleles of TEF2 that cause increased suppression of frameshift mutations also suppressed the lethality of tef5::TRP1. Most of the strains in which tef5::TRP1 is suppressed by dominant mutant alleles of TEF2 grew more slowly and were more antibiotic sensitive than strains with tef5::TRP1 is suppressed by wild-type TEF2. Two alleles, TEF2-4 and TEF2-10, interact with tef5::TRP1 to produce strains that showed doubling times similar to tef5::TRP1 strains containing extra copies of wild-type TEF2. These strains were less cold sensitive, drug sensitive and correspondingly less efficient suppressor of +1 frameshift mutations. These phenotypes indicate that translation and cell growth are highly sensitive to changes in EF-1alpha and EF-1beta activity.
Kinzy
T G
TG
Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Woolford
J L
JL
D000483:Alleles; D015870:Gene Expression; D005799:Genes, Dominant; D005800:Genes, Fungal; D005804:Genes, Lethal; D005838:Genotype; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors / Q000096:biosynthesis* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D013045:Species Specificity; D013489:Suppression, Genetic; D013696:Temperature
D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate