ER-to-Golgi trafficking of procollagen in the absence of large carriers.
JOURNAL OF CELL BIOLOGY(2019)
摘要
Secretion and assembly of collagen are fundamental to the function of the extracellular matrix. Defects in the assembly of a collagen matrix lead to pathologies including fibrosis and osteogenesis imperfecta. Owing to the size of fibril-forming procollagen molecules it is assumed that they are transported from the endoplasmic reticulum to the Golgi in specialized large COP II-dependent carriers. Here, analyzing endogenous procollagen and a new engineered GFP-tagged form, we show that transport to the Golgi occurs in the absence of large (>350 nm) carriers. Large GFP-positive structures were observed occasionally, but these were nondynamic, are not COP II positive, and are labeled with markers of the ER. We propose a short-loop model of COP II-dependent ER-to-Golgi traffic that, while consistent with models of ERG IC-dependent expansion of COP II carriers, does not invoke long-range trafficking of large vesicular structures. Our findings provide an important insight into the process of procollagen trafficking and reveal a short-loop pathway from the ER to the Golgi, without the use of large carriers.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要