RUN Domain And Cysteine Rich Domain Containing, Beclin 1 Interacting Protein (Rubicon)

Mouse Rubicon coimmunoprecipitated with endogenous beclin-1 (BECN1) and Vps34 (PIK3C3), which are essential components of a protein complex that regulates autophagy. Mutation analysis revealed that the central coiled-coil domains of Rubicon were required for the interaction of Rubicon with beclin-1 and Vps34. Gel filtration experiments revealed that endogenous Vps34, beclin-1, Atg14, and Rubicon coeluted in a complex of over 700 kD. However, immunoprecipitation analysis showed that Atg14 and Rubicon did not always coimmunoprecipitate in the same complex. Knockdown of Rubicon via small interfering RNA enhanced the autophagy-mediated clearance of a test substrate. Rubicon specifically inhibited the kinase activity of human VPS3