Análisis del papel del pie de la RNA polimerasa II de Saccharomyces cerevisiae y su importancia en múltiples etapas de la transcripción

Abstract

Little is known about the mechanisms governing the nuclear assembly, stability, degradation, and recycling of RNA polymerase II. We demonstrate that the foot ofthe RNA pol II is crucial for the assembly and stability ofthe complex, by ensuring the correct association of Rpb l-Rpb6, and of the dimer Rpb4/7. Mutations at the foot affect the assembly and stability ofthe enzyme, a defect that is offset by RPB6 overexpression, cause Rpbl degradation in the nuc\eus by an Rsp5-dependent mechanism, and leads to alterations in several transcription steps. Assembly defect alter transcriptional activity, the amount of enzyme associated with the genes, the CTD phosphorylation, interferes with mRNA capping machinery, suggest an increase in stalled RNA pol II and alter the PIC stability. Foot mutants show a stress response and a reduction in the amount of mRNA bound to Rpb4/7, affecting the mRNA decay.