Regulation of EXLA1 Stability by E3 Ubiquitin Ligase GW2 in Rice

Abstract

Grain Weight 2 (GW2), known as the E3 ubiquitin ligase, important role in

controlling the size and weight of the grains. Such gene expression and regulation

by GW2 has been studied for a long time. Nevertheless, the post-translational

research of GW2 rarely progressed. Previous studies have confirmed in vitro that

Grain Weight 2 (GW2) in rice could act as an E3 ubiquitin ligase for EXPANSIN

LIKE 1 (EXLA1). Here, we showed that Grain Weight2 (GW2) could regulation

EXLA1 stability. In this paper, particle bombardment experiments showed that

GW2 and EXLA1 interacted in epidermal cells of onion. The yeast two-hybrid

experiment also confirmed that the expansin family except EXLA1 did not bind to

GW2. In addition, the expression of EXLA1 was found to be high in the gw2

mutant and the expression of EXLA1 was found to be different when GA3,

Cytokinin, and Auxin were treated to the WT Norin. We also found that BSG1,

a candidate group other than EXLA1, binds to GW2 through yeast two-hybrid

experiments and in vitro pull down experiments. Taken together, we confirmed that

the stability of EXLA1 was regulated by GW2, and confirmed that it binds to a

candidate group other than EXLA1.