Arabidopsis RAD23B regulates pollen development by mediating KRP1 degradation

LAN, LI; BIN, LI; BORASSI, CECILIA; ESTEVEZ, JOSE MANUEL; XIUSHAN, LI; XUANMING, LIU

JOURNAL OF EXPERIMENTAL BOTANY

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2020

0022-0957

The ubiquitin (Ub)/26S proteasomesystem (UPS) plays a key role in the plant growth, development, and survival bydirecting the turnover of numerous regulatory proteins. In UPS, ubiquitin-like(UBL) and ubiquitin-associated (UBA) domains function as hubs forubiquitin-mediated protein degradation. RADIATION SENSITIVE23 (RAD23), whichwas identified as a UBL/UBA protein, contributed to cell cycle progression,stress response, ER proteolysis, and DNA repair. Here, we report pollen isarrested at the microspore stage in a null rad23b mutant. We demonstrated that RAD23Bcan directly interact with KIP-RELATED PROTEIN 1 (KRP1) through its UBL-UBAdomains. In addition, overexpression of KRP1 resulted in pollen developmentdefects, a phenotype similar to the rad23b mutant. Finally, RAD23B was found to promote the degradation ofKRP1 in vivo, which was accumulatedfollowing treatment with MG132. In summary, these results indicate theimportant role of RAD23B in pollen development by controlling turnover of a keycell cycle protein, KRP1.