The Pathway of Collagen Secretion

摘要: COPII vesicles mediate export of secretory cargo from the endoplasmic reticulum (ER). However, a standard vesicle with diameter 60-90 nm is too small to collagens that are composed rigid triple helices up 400 in length. How do cells pack and secrete such bulky molecules? This issue fundamentally important, as constitute approximately 25% our dry body weight essential for almost all cell-cell interactions. Recently, potential mechanism biogenesis mega-transport carriers was identified, involving packing increasing size coats. Packing mediated by TANGO1, which binds procollagen VII lumen interacts proteins Sec23/Sec24 on cytoplasmic side ER. Cullin3, an E3 ligase, its specific adaptor protein, KLHL12, ubiquitinate Sec31, could increase Recruitment these their interactors into COPII-mediated may be needed Nonetheless, we present alternative pathway TANGO1 cooperate without generating carrier.