Translation termination factors function outside of translation: yeast eRF1 interacts with myosin light chain, Mlc1p, to effect cytokinesis.
The translation termination factor eRF1 recognizes stop codons at the A site of the ribosome and induces peptidyl-tRNA hydrolysis at the peptidyl transferase centre. Recent data show that, besides translation, yeast eRF1 is also involved in cell cycle regulation. To clarify the mechanisms of non-translational functions of eRF1, we performed a genetic screen for its novel partner proteins. This screen revealed the gene for myosin light chain, Mlc1p, acting as a dosage suppressor of a temperature-sensitive mutation in the SUP45 gene encoding eRF1. eRF1 and Mlc1p are able to interact with each other and, similarly to depletion of Mlc1p, mutations in the SUP45 gene may affect cytokinesis. Immunofluorescent staining performed to determine localization of Mlc1p has shown that the sup45 mutation, which arrests cytokinesis, redistributed Mlc1p, causing its disappearance from the bud tip and the bud neck. The data obtained demonstrate that yeast eRF1 has an important non-translational function effecting cytokinesis via interaction with Mlc1p.
Valouev
I A
IA
Institute of Experimental Cardiology, Cardiology Research Center, 3rd Cherepkovskaya Street 15A, 121552 Moscow, Russia.
Urakov
V N
VN
Kochneva-Pervukhova
N V
NV
Smirnov
V N
VN
Ter-Avanesyan
M D
MD
D048749:Cytokinesis; D003593:Cytoplasm / Q000737:chemistry; D005800:Genes, Fungal; D016153:Genes, Suppressor; D009154:Mutation; D018994:Myosin Light Chains / Q000235:genetics / Q000502:physiology*; D010443:Peptide Chain Termination, Translational; D010454:Peptide Termination Factors / Q000235:genetics / Q000502:physiology*; D011233:Precipitin Tests; D011485:Protein Binding; D014176:Protein Biosynthesis; D025941:Protein Interaction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology*; D013489:Suppression, Genetic
C113979:MLC1 protein, S cerevisiae; D018994:Myosin Light Chains; D010454:Peptide Termination Factors; D029701:Saccharomyces cerevisiae Proteins