Rab46 integrates Ca
2+ and histamine signaling to regulate selective cargo release from Weibel-Palade bodies.
J Cell Biol 2019;
218:2232-2246. [PMID:
31092558 PMCID:
PMC6605797 DOI:
10.1083/jcb.201810118]
[Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 03/24/2019] [Accepted: 04/22/2019] [Indexed: 12/12/2022] Open
Abstract
It is unclear how a plethora of stimuli evoke differential cargo secretion from endothelial cells to produce stimulus-appropriate responses. Miteva et al. show that Rab46 integrates histamine signaling and Ca2+ signals to regulate selective cargo release from Weibel-Palade bodies.
Endothelial cells selectively release cargo stored in Weibel-Palade bodies (WPBs) to regulate vascular function, but the underlying mechanisms are poorly understood. Here we show that histamine evokes the release of the proinflammatory ligand, P-selectin, while diverting WPBs carrying non-inflammatory cargo away from the plasma membrane to the microtubule organizing center. This differential trafficking is dependent on Rab46 (CRACR2A), a newly identified Ca2+-sensing GTPase, which localizes to a subset of P-selectin–negative WPBs. After acute stimulation of the H1 receptor, GTP-bound Rab46 evokes dynein-dependent retrograde transport of a subset of WPBs along microtubules. Upon continued histamine stimulation, Rab46 senses localized elevations of intracellular calcium and evokes dispersal of microtubule organizing center–clustered WPBs. These data demonstrate for the first time that a Rab GTPase, Rab46, integrates G protein and Ca2+ signals to couple on-demand histamine signals to selective WPB trafficking.
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