MARK2/EMK1/Par-1Bα phosphorylation of Rab11-family interacting protein 2 is necessary for the timely establishment of polarity in Madin-Darby canine kidney cells

NA Ducharme, CM Hales, LA Lapierre… - Molecular biology of …, 2006 - Am Soc Cell Biol
NA Ducharme, CM Hales, LA Lapierre, AJL Ham, A Oztan, G Apodaca, JR Goldenring
Molecular biology of the cell, 2006Am Soc Cell Biol
Rab11a, myosin Vb, and the Rab11-family interacting protein 2 (FIP2) regulate plasma
membrane recycling in epithelial cells. This study sought to characterize more fully Rab11-
FIP2 function by identifying kinase activities modifying Rab11-FIP2. We have found that
gastric microsomal membrane extracts phosphorylate Rab11-FIP2 on serine 227. We
identified the kinase that phosphorylated Rab11-FIP2 as MARK2/EMK1/Par-1Bα (MARK2),
and recombinant MARK2 phosphorylated Rab11-FIP2 only on serine 227. We created …
Rab11a, myosin Vb, and the Rab11-family interacting protein 2 (FIP2) regulate plasma membrane recycling in epithelial cells. This study sought to characterize more fully Rab11-FIP2 function by identifying kinase activities modifying Rab11-FIP2. We have found that gastric microsomal membrane extracts phosphorylate Rab11-FIP2 on serine 227. We identified the kinase that phosphorylated Rab11-FIP2 as MARK2/EMK1/Par-1Bα (MARK2), and recombinant MARK2 phosphorylated Rab11-FIP2 only on serine 227. We created stable Madin-Darby canine kidney (MDCK) cell lines expressing enhanced green fluorescent protein-Rab11-FIP2 wild type or a nonphosphorylatable mutant [Rab11-FIP2(S227A)]. Analysis of these cell lines demonstrates a new role for Rab11-FIP2 in addition to that in the plasma membrane recycling system. In calcium switch assays, cells expressing Rab11-FIP2(S227A) showed a defect in the timely reestablishment of p120-containing junctional complexes. However, Rab11-FIP2(S227A) did not affect localization with recycling system components or the normal function of apical recycling and transcytosis pathways. These results indicate that phosphorylation of Rab11-FIP2 on serine 227 by MARK2 regulates an alternative pathway modulating the establishment of epithelial polarity.
Am Soc Cell Biol