Sorting nexin 16 regulates EGF receptor trafficking by phosphatidylinositol-3-phosphate interaction with the Phox domain.
Sorting nexins (SNXs) containing the Phox (PX) domain are implicated in the regulation of membrane trafficking and sorting processes of epithelial growth factor receptor (EGFR). In this study, we investigated whether SNX16 regulates EGF-induced cell signaling by regulating EGFR trafficking. SNX16 is localized in early and recycling endosomes via its PX domain. Mutation of the PX domain disrupted the association between SNX16 and phosphatidylinositol 3-phosphate [PtdIns(3)P]. Treatment with wortmannin, a PtdIns 3-kinase inhibitor, abolished the endosomal localization of SNX16, suggesting that the intracellular localization of SNX16 is regulated by PtdIns 3-kinase activity. SNX16 was found to associate with EGFR after stimulation with EGF in COS-7 cells. Moreover, overexpression of SNX16 increased the rate of EGF-induced EGFR degradation and inhibited the EGF-induced up-regulation of ERK and serum response element (SRE). In addition, mutation in the PX domain significantly blocked the inhibitory effect of SNX16 on EGF-induced activation of ERK and SRE. From these results, we suggest that SNX16 directs the sorting of EGFR to the endosomal compartment and thus regulates EGF-induced cell signaling.
Choi
Jang Hyun
JH
Division of Molecular and Life Science, Pohang University of Science and Technology, San 31, Hojadong, Pohang, Kyungbuk 790-784, Republic of Korea.
Hong
Won-Pyo
WP
Kim
Myong Jong
MJ
Kim
Jae Ho
JH
Ryu
Sung Ho
SH
Suh
Pann-Ghill
PG
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002451:Cell Compartmentation / Q000187:drug effects / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D016716:PC12 Cells; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011940:Receptor Aggregation / Q000187:drug effects / Q000502:physiology; D027602:Serum Response Element / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D058305:Sorting Nexins; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D033921:Vesicular Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D004791:Enzyme Inhibitors; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D048049:Extracellular Signal-Regulated MAP Kinases; D019869:Phosphatidylinositol 3-Kinases; D058305:Sorting Nexins; D033921:Vesicular Transport Proteins; C477748:SNX16 protein, human