Abstract
Nonfunctional Rurm1 (Rice ubiquitin-related modifier-1) mutant line IM294 shows various aberrant phenotypes, such as a slender glume, a delay in heading date, an increase in the sterility rate, and a decrease in the germination rate. Like other ubiquitin-like proteins, the RURM1 protein is considered to be involved in these phenotypes by regulating the activity or function of target proteins. However, protein-modification function of RURM1 is not well understood. In order to elucidate the molecular function of the RURM1 protein, we aimed to identify the target proteins for RURM1 using transgenic rice overexpressing the Rurm1 gene. We obtained ten transgenic rice plants overexpressing the Rurm1 gene from 253 calli derived from the matured seeds of Nipponbare. When we performed western blot analysis against the RURM1 protein using crude protein extracted from transgenic rice plants, we detected four bands of 110, 52, 39, and 24 kDa. This indicates that the RURM1 protein harbors protein-modification function in rice.
