Retromer maintains basolateral distribution of the type II TGF-? receptor via the recycling endosome.

ABSTRACT: Transforming growth factor ? (TGF-?) is critical for the development and maintenance of epithelial structures. Because receptor localization and trafficking affect the cellular and organismal response to TGF-?, the present study was designed to address how such homeostatic control is regulated. To that end, we identify a new role for the mammalian retromer complex in maintaining basolateral plasma membrane expression of the type II TGF-? receptor (T?RII). Retromer and T?RII associate in the presence or absence of TGF-? ligand. After retromer knockdown, although T?RII internalization and trafficking to a Rab5-positive compartment occur as in wild-type cells, receptor recycling is inhibited. This results in T?RII mislocalization from the basolateral to both the basolateral and apical plasma membranes independent of Golgi transit and the Rab11-positive apical recycling endosome. The data support a model in which, after initial basolateral T?RII delivery, steady-state polarized T?RII expression is maintained by retromer/T?RII binding and delivery to the common recycling endosome.

SUBMITTER: Yin X 

PROVIDER: S-EPMC3708733 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature