TTC5 mediates autoregulation of tubulin via mRNA degradation

Abstract

Mechanism of tubulin autoregulation Cells tightly control the abundance of key housekeeping factors, such as ribosomes and chaperones, to maintain them at optimal levels needed for homeostasis. Most abundance control mechanisms involve feedback regulation of mRNA transcription, but others, such as tubulins, are regulated by highly specific mRNA degradation. Lin et al. found that tetratricopeptide protein 5 (TTC5) binds to nascent alpha and beta tubulins on translating ribosomes to trigger degradation of their associated mRNAs when excess tubulin is present (see the Perspective by Shoshani and Cleveland). In the absence of TTC5-mediated tubulin autoregulation, cells display error-prone chromosome segregation, a process critically dependent on tubulin concentration. Science , this issue p. 100 ; see also p. 29