Carnegie Mellon University
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Sequence-dependent sorting of recycling proteins by actin-stabilized endosomal microdomains.

journal contribution
posted on 2010-11-24, 00:00 authored by Manojkumar PuthenveeduManojkumar Puthenveedu, Benjamin Lauffer, Paul Temkin, Rachel Vistein, Peter Carlton, Kurt Thorn, Jack Taunton, Orion D. Weiner, Robert G. Parton, Mark von Zastrow

The functional consequences of signaling receptor endocytosis are determined by the endosomal sorting of receptors between degradation and recycling pathways. How receptors recycle efficiently, in a sequence-dependent manner that is distinct from bulk membrane recycling, is not known. Here, in live cells, we visualize the sorting of a prototypical sequence-dependent recycling receptor, the beta-2 adrenergic receptor, from bulk recycling proteins and the degrading delta-opioid receptor. Our results reveal a remarkable diversity in recycling routes at the level of individual endosomes, and indicate that sequence-dependent recycling is an active process mediated by distinct endosomal subdomains distinct from those mediating bulk recycling. We identify a specialized subset of tubular microdomains on endosomes, stabilized by a highly localized but dynamic actin machinery, that mediate this sorting, and provide evidence that these actin-stabilized domains provide the physical basis for a two-step kinetic and affinity-based model for protein sorting into the sequence-dependent recycling pathway.

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Date

2010-11-24