26S proteasome regulates the degradation of microtubule

Abstract:

To analyze the degradation mechanism of microtubules protein in the plant cell, we used anti-MT, proteasome inhibitor MG132 combining the in vivo and in vitro techniques of genetics and plant molecular biology to reveal that the degradation of TUA and TUB was mediated by the ubiquitin/26S proteasome. Our results indicated that in the loss of function mutant rpn 10-1 of regulatory subunit RPN10 of the 26S proteasome, the degradation of TUB was impaired while that of TUA was not affected, as compared with wild type plants. Meanwhile, overexpression of TUA in mutant rpn 10-1 increased the root length while overexpression of TUB inhibited root elongation of rpn 10-1and the ratio of TUA to TUB were an imbalance in mutant rpn 10-1, which suppressed the root growth. Together, our results indicated that 26S proteasome is required for the degradation of tubulins (TUA and TUB) and RPN10 can influence plant growth by regulating protein stability of TUB.

Key words:Microtubule; 26S proteasome; Protein degradation; Arabidopsis