| Beclin 1 was originally identified as a novel Bcl 2 interacting protein , but co immunoprecipitation studies suggest that the major physiological partner for Beclin 1 is the mammalian class 3 phosphatidylinositol 3 kinase ( PI 3 kinase ) Vps 34 . ^^^ Beclin 1 has been proposed to function as a tumor suppressor by promoting cellular macroautophagy , a process that is known to depend on Vps 34 . ^^^ However , an alternative role for Beclin 1 in modulating normal Vps 34 dependent protein trafficking pathways has not been ruled out . ^^^ Immunoprecipitates of endogenous Beclin 1 contained human Vps 34 ( hVps 34 ) , but not Bcl 2 . ^^^ |