Abstract
COP9 signalosome (CSN) is a conserved protein complex that is known to regulate ubiquitin-proteasome mediated protein degradation pathway. CSN is composed of eight subunits designated CSN1 to CSN8 according to their sizes. Each subunit has unique roles and specific functions in the complex. In order to dissect the function of CSN, we focus on analyzing the specific function of CSN1 in the model plant, Arabidopsis.
SAP130 is one of the identified CSN1 binding proteins. SAP130 is a component of the SF3b complex which is involved in mRNA splicing. In Arabidopsis, SAP130 was coded by two genes (AtSAP130a and AtSAP130b) which both map on chromosome 3. The mRNA for both genes were detected in all observed organs. Pull down and immunoprecipitation revealed that AtSAP130 C-terminus directly bound AtCSN1 N-terminus. Here we discuss the possible role of CSN function in post-transcriptional regulation in Arabidopsis.
