Functional analysis of ubiquitin conjugating enzymes in Caenorhabditis elegans

Ubiquitination is one of the main post-translational protein modifications required for transmitting unique protein regulatory signals. Ubiquitination involves the attachment of single or multiple ubiquitin molecules to the target proteins. E1, E2 and E3 enzymes are involved in the ubiquitination pathway. In this study, RNAi was used to silence individual E2s and combinations of E2s in Caenorhabditis elegans and the resulting lack of function phenotypes and embryonic lethality effects were observed. The results of this study indicated that out of all the E2s, only ubc-2 showed significant embryonic lethality effect. ubc-2 also showed an interaction with an E3 called anaphase promoting complex suggesting the involvement of ubc-2 in cell cycle regulation. The combinational RNAi treatments in this study revealed six lethal 5 E2 combinations and two lethal 4 E2 combinations indicating redundancies in the ubc class of enzymes.