Identification of potential targets of protease RhoII in Haloferax volcanii using proteomics

CERLETTI M.; DE CASTRO R.E.; POETSCH A.; GIMÉNEZ M.I.; COSTA M.I.; TROTSCHEL C.

Córdoba

Congreso; LII Reunión SAIB 2016; 2016

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

Rhomboid proteases are a family of membrane serine proteases present in the three Domains of Life. These enzymes have a role in gene regulation and cellular signalling, but little is known about their targets in Archaea. In Haloferax volcanii a chromosomal deletion strain of rhoII (MIG1) showed reduced motility, increased sensitivity to novobiocin, impaired recovery after UV irradiation, and a defect in S-layer glycosylation.To understand the impact of eliminating rhoII of H. volcanii chromosome a differential proteomics approach was used comparing membrane and cytosolic fractions of exponential and stationary phase cultures from MIG1 and the parental strain (H26). A 34% of the total proteome was detected, including 241 differentially expressed proteins. RhoII could have direct impact over potential targets and indirect effect on other proteins not predicted as substrates. Data analysis exposed halocyanin as a potential target and several differential proteins related with MIG1 phenotipes like PibD (motility), DNA gyrase A (novobiocin sensitivity), RecA/B (UV repair) and glycosyltransferases (Agl12, HVO_2989). These results show that deletion of the RhoII gene has a global effect on H. volcanii proteome and expose possible substrates which, if experimentally validated, will provide information on the role of rhomboid proteases in Archaea.