title: mVps24p functions in EGF receptor sorting/trafficking from the early endosome.
abstract: Yeast Vps24p (vacuolar protein sorting) is part of a protein complex suggested to function in sorting/trafficking during endocytosis. We have characterized a mammalian homolog of the yeast protein, mVps24p, and examined its role in epidermal growth factor receptor trafficking. Endogenous mVps24p was distributed in both cytosol and in puncta and partially colocalized with markers for the trans-Golgi network. Adventitious expression of hrs or a mVps4p mutant deficient in ATPase activity caused a redistribution of both mVps24p and the M6PR to the resultant clustered/enlarged early endosomes. Expression of an mVps24p N-terminal fragment, that interacts with phosphatidylinositol 3,5-bisphosphate but not with mVps4p, produces enlarged early endosomes. More importantly, the mVps24p N-terminal fragment resulted in not only enhanced recycling, but also decreased degradation of the EGF receptor. These findings are consistent with a model in which mVps24p has a role in trafficking from the early endosome.
authors.affiliation: Department of Neurobiology and Anatomy, The University of Texas Medical School at Houston, 6431 Fannin Street, MSB 7.007, Houston, TX 77030, USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yan
authors.forename: Piper Reid
authors.initials: PR
authors.lastname: Hunt
authors.forename: Laurence
authors.initials: L
authors.lastname: Frelin
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Vida
authors.forename: Jonathan
authors.initials: J
authors.lastname: Pevsner
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Bean
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D056827:Endosomal Sorting Complexes Required for Transport; D011992:Endosomes / Q000737:chemistry / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D021381:Protein Transport; D016415:Sequence Alignment; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000502:physiology*
chemical_list: C498543:CHMP3 protein, human; C478390:Chmp3 protein, mouse; D056827:Endosomal Sorting Complexes Required for Transport; D033921:Vesicular Transport Proteins; D066246:ErbB Receptors