The Translocon Sec61β Localized in the Inner Nuclear Membrane Transports Membrane-embedded EGF Receptor to the Nucleus

• DOI: 10.1074/jbc.m110.158659
• Publication Date: 2010-10-12T05:25:21Z
• Authors: Ying-Nai Wang; Hirohito Yamaguchi; Longfei Huo; Yi Du; Hong-Jen Lee; Heng-Huan Lee; Hongmei Wang; Jung-Mao Hsu; Mien-Chie Hung
• Keywords: Nucleoplasm; Importin; Nuclear pore; Sec61; Nuclear membrane

Accumulating evidence indicates that endocytosis plays an essential role in the nuclear transport of ErbB family members, such as epidermal growth factor receptor (EGFR) and ErbB-2. Nevertheless, how full-length receptors embedded endosomal membrane pass through pore complexes function non-membrane-bound nucleus remains unclear. Here we show upon EGF treatment, biotinylated cell surface EGFR is trafficked to inner (INM) complexes, remaining a membrane-bound environment. We further find importin β regulates INM addition nucleus/nucleoplasm. Unexpectedly, well known endoplasmic reticulum associated translocon Sec61β found reside associate with EGFR. Knocking down expression reduces level nucleoplasm portion accumulates it portion. Thus, unrecognized release membrane-anchored from lipid bilayer nucleus. The newly identified provides alternative pathway for can be utilized by membrane-embedded proteins