AP-1 and KIF13A coordinate endosomal sorting and positioning during melanosome biogenesis

1. J Cell Biol. 2009 Oct 19;187(2):247-64. doi: 10.1083/jcb.200907122.

AP-1 and KIF13A coordinate endosomal sorting and positioning during melanosome

Delevoye C(1), Hurbain I, Tenza D, Sibarita JB, Uzan-Gafsou S, Ohno H, Geerts WJ,
Verkleij AJ, Salamero J, Marks MS, Raposo G.

Author information:
(1)Structure and Membrane Compartments, Centre Nationale de la Recherche
Scientifique, UMR 144 Institut Curie, Centre de Recherche, Paris F-75248, France.

Comment in
J Cell Biol. 2009 Oct 19;187(2):161-3.

Specialized cell types exploit endosomal trafficking to deliver protein cargoes
to cell type-specific lysosome-related organelles (LROs), but how endosomes are
specified for this function is not known. In this study, we show that the
clathrin adaptor AP-1 and the kinesin motor KIF13A together create peripheral
recycling endosomal subdomains in melanocytes required for cargo delivery to
maturing melanosomes. In cells depleted of AP-1 or KIF13A, a subpopulation of
recycling endosomes redistributes to pericentriolar clusters, resulting in
sequestration of melanosomal enzymes like Tyrp1 in vacuolar endosomes and
consequent inhibition of melanin synthesis and melanosome maturation.
Immunocytochemistry, live cell imaging, and electron tomography reveal AP-1- and
KIF13A-dependent dynamic close appositions and continuities between peripheral
endosomal tubules and melanosomes. Our results reveal that LRO protein sorting is
coupled to cell type-specific positioning of endosomes that facilitate
endosome-LRO contacts and are required for organelle maturation.

DOI: 10.1083/jcb.200907122
PMCID: PMC2768840
PMID: 19841138 [Indexed for MEDLINE]

Know more about