Plays a role in the regulation of starvation-induced autophagosome formation. Together with the TRAPPIII complex, regulates a constitutive trafficking step from peripheral recycling endosomes to the early Golgi, maintaining the cycling pool of ATG9 required for initiation of autophagy. Interacts with ULK1. May interact with RAB11A and RAB11B, but does not exhibit any GTPase-activating activity toward these proteins. Interacts with TRAPPC8. After amino acid starvation, Golgi apparatus-associated protein levels increase compared with fed conditions. May be cycling between the Golgi apparatus and an endosomal pool, redistributing to the Golgi apparatus upon starvation. PubMed:15758561 detected expression at the stage of sexual maturation in testis, mainly in the spermatocytes. No expression detected in the ovary, brain, heart, lung, liver and kidney. PubMed:15200410 detected expression in brain, heart, lung, liver, spleen and kidney but not in small intestine. First detected in the testis at 5 weeks. Level of expression increases up to 7 weeks and maintains even at 63 weeks. Up-regulated in nephrectomized kidney. Extended N-terminus.