Interaction
of Rpg1p with Sla2p in Saccharomyces cerevisiae.
Filip Janda,
Ivana Janatova, Alena Jiraskova, Katerina Malinska, Jiri Hasek
Lab. of Cell Reproduction, Institute of Microbiology, Videnska 1083, Prague 4,
142 20, Czech Republic (jandaf@biomed.cas.cz)
The gene RPG1/TIF32 of Saccharomyces cerevisiae encodes the largest subunit of translation initiation factor eIF3. In addition to its essential role in translation initiation Rpg1p interacts with microtubules, influences some nonessential cellular processes such as recovery of microtubules after nocodazole treatment and interacts with proteins that are not directly involved in translation. One of these is Sla2p that is associated with actin in cortical actin patches. Sla2p affects endocytosis and cell polarity. In this work we report that Rpg1p is probably present at the same protein complex as Sla2p. We used cytoplasmic two-hybrid system (CytotrapTM) in search for interaction domains of both proteins. We also performed coimmunoprecipitation experiments using yeast strains carrying SLA2 truncations. In accordance with previous two-hybrid experiments we found that aminoacid residues 391-397 of Rpg1p affect interaction with Sla2p in CytotrapTM system. Such deletion of Rpg1p does not affect translation. Further we prepared seven deletions of Sla2p and tested their interaction with Rpg1p using CytotrapTM. We found that C-terminus of Sla2p namely amino acid residues 501-968 are sufficient for detection of interaction in this system. Function of the interaction is still unknown and demands subsequent research. The work was supported by GACR 204/02/1424 and Institutional Research Concept No. AVOZ5020903.