Document Type

Article

Publication Title

Journal of Cell Biology

Publication Date

11-20-2004

Volume

167

Issue

6

Disciplines

Biology | Life Sciences

Abstract

What is the first membrane fusion step in the secretory pathway? In mammals, transport vesicles coated with coat complex (COP) II deliver secretary cargo to vesicular tubular clusters (VTCs) that ferry cargo from endoplasmic reticulum exit sites to the Golgi stack. However, the precise origin of VTCs and the membrane fusion step(s) involved have remained experimentally intractable. Here, we document in vitro direct tethering and SNARE-dependent fusion of endoplasmic reticulum-derived COPII transport vesicles to form larger cargo containers. The assembly did not require detectable Golgi membranes, preexisting VTCs, or CON function. Therefore, COPII vesicles appear to contain all of the machinery to initiate VTC biogenesis via homotypic fusion. However, COPI function enhanced VTC assembly, and early VTCs acquired specific Golgi components by heterotypic fusion with Golgi-derived CON vesicles.

DOI

10.1083/jcb.200408135

Comments

© 2004, authors. Produced here by Rockefeller University Press.

Rights

© 2004, authors. Produced here by Rockefeller University Press.

Creative Commons License

Creative Commons Attribution 3.0 License
This work is licensed under a Creative Commons Attribution 3.0 License.

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