Arp2/3 complex and Mps3 are required for regulation of ribosome biosynthesis in the secretory stress response

作者：Yabuki Yukari; Katayama Masako; Kodama Yushi; Sakamoto Akiko; Yatsuhashi Ayumi; Funato Kouichi^*; Mizuta Keiko^*

来源：Yeast, 2017, 34(4): 155-163.

DOI：10.1002/yea.3221

• ribosome biogenesis
• secretory defect
• Arp2
• 3 complex
• actin
• spindle pole body
• Mps3

Secretory defects cause transcriptional repression of ribosome biogenesis in Saccharomyces cerevisiae. However, the molecular mechanism underlying secretory defect-induced transcriptional repression of ribosome biogenesis remains to be fully elucidated. In this study, we demonstrated that the Arp2/3 complex was required for reduction of ribosome protein gene expression in response to defective secretion by addition of tunicamycin. Two cmd1 mutants, cmd1-228 and cmd1-239 that cause mislocalization of calmodulin and defective mitotic spindle formation, respectively, failed to interact with Arc35, a component of the Arp2/3 complex. These mutants also caused defects in the reduction of ribosome protein gene expression induced by secretory blockade. A mutation in TUB4 (tub4-1), whose product has an essential function in microtubule organization, showed a similar response. In addition, we showed that the response to a secretory defect required SUN protein Mps3, which was localized at the nuclear envelope and involved in spindle pole body assembly. These results suggest that the Arp2/3 complex is required to transmit signals resulting from secretory blockade, and that the spindle pole body functions as a transit point from cytoplasm to Mps3 at the nuclear envelope.

• 出版日期2017-4