Sequence-Dependent Sorting of Recycling Proteins by Actin-Stabilized Endosomal Microdomains

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.cell.2010.10.003 Byline: Manojkumar A. Puthenveedu (1), Benjamin Lauffer (2), Paul Temkin (2), Rachel Vistein (1), Peter Carlton (3), Kurt Thorn (4), Jack Taunton (5), Orion D. Weiner (4), Robert G. Parton (6), Mark von Zastrow (2)(5) Keywords: CELLBIO; SIGNALING Abstract: 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. Author Affiliation: (1) Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA (2) Department of Psychiatry, University of California at San Francisco, San Francisco, CA 94158, USA (3) Department of Physiology, University of California at San Francisco, San Francisco, CA 94158, USA (4) Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA 94158, USA (5) Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA 94158, USA (6) The University of Queensland, Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, St. Lucia, Queensland 4072, Australia 8 Article History: Received 31 October 2009; Revised 7 April 2010; Accepted 27 September 2010 Article Note: (miscellaneous) Published: November 24, 2010