An Endosomal NAADP-Sensitive Two-Pore Ca2+ Channel Regulates ER-Endosome Membrane Contact Sites to Control Growth Factor Signaling

Autor: Bethan S. Kilpatrick, Emily R. Eden, Leanne N. Hockey, Elizabeth Yates, Clare E. Futter, Sandip Patel
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Cell Reports, Vol 18, Iss 7, Pp 1636-1645 (2017)
Druh dokumentu: article
ISSN: 2211-1247
DOI: 10.1016/j.celrep.2017.01.052
Popis: Membrane contact sites are regions of close apposition between organelles that facilitate information transfer. Here, we reveal an essential role for Ca2+ derived from the endo-lysosomal system in maintaining contact between endosomes and the endoplasmic reticulum (ER). Antagonizing action of the Ca2+-mobilizing messenger NAADP, inhibiting its target endo-lysosomal ion channel, TPC1, and buffering local Ca2+ fluxes all clustered and enlarged late endosomes/lysosomes. We show that TPC1 localizes to ER-endosome contact sites and is required for their formation. Reducing NAADP-dependent contacts delayed EGF receptor de-phosphorylation consistent with close apposition of endocytosed receptors with the ER-localized phosphatase PTP1B. In accord, downstream MAP kinase activation and mobilization of ER Ca2+ stores by EGF were exaggerated upon NAADP blockade. Membrane contact sites between endosomes and the ER thus emerge as Ca2+-dependent hubs for signaling.
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