Regulation of aleurone cell fate determinants in Zea mays

Abstract

The ability to perceive and transduce signals in a range of plant responses is mediated through receptor kinases. ARABIDOPSIS CRINKLY4 (ACR4) is unique among known plant receptor kinases because functional receptors appear to rapidly turnover. In this study, we identified CSN5 subunits of the COP9Siganalosome (CSN) as interactors of cytoplasmic domain of ACR4. In-vitro interactions confirmed that CSN5 subunits bind and are phosphorylated by ACR4. In-vivo FRET experiments demonstrated that ACR4 was in close proximity to CSN5 within the context of a plant cell. In-planta evidence was demonstrated by the accumulation of ACR4-GFP in transgenic plants treated with curcumin, a COP9 siganalosome inhibitor. In addition, ACR4-GFP accumulated in a csn5 double mutant background. Thus, the COP9 siganalosome appears to be involved in the turnover of ACR4. 1. Genetics, Development and Cell Biology Department, Iowa State University 2. Molecular, Cellular and Developmental Biology Program, Iowa State University 3. Interdepartmental Plant Biology Major, Iowa State University 4. Agronomy Department, Iowa State University