JCB logo
R&D Systems: New Poster Available
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 928K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Toyooka, K.
Right arrow Articles by Minamikawa, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Toyooka, K.
Right arrow Articles by Minamikawa, T.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

© The Rockefeller University Press, 0021-9525/2000//453 $5.00
The Journal of Cell Biology, Volume 148, Number 3, , 2000 453-464

Original Article

Mass Transport of Proform of a Kdel-Tailed Cysteine Proteinase (Sh-EP) to Protein Storage Vacuoles by Endoplasmic Reticulum–Derived Vesicle Is Involved in Protein Mobilization in Germinating Seeds



Kiminori Toyookaa, Takashi Okamotoa, and Takao Minamikawaa

a Department of Biological Sciences, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji, Tokyo, 192-0397 Japan
Department of Biological Sciences, Tokyo Metropolitan University, Minami-osawa, Hachioji, Tokyo, 192-0397 Japan.+81 426-77-2559+81 426-77-2559

okamoto-takashi{at}c.metro-u.ac.jp

A vacuolar cysteine proteinase, designated SH-EP, is expressed in the cotyledon of germinated Vigna mungo seeds and is responsible for the degradation of storage proteins. SH-EP is a characteristic vacuolar proteinase possessing a COOH-terminal endoplasmic reticulum (ER) retention sequence, KDEL. In this work, immunocytochemical analysis of the cotyledon cells of germinated V. mungo seeds was performed using seven kinds of antibodies to identify the intracellular transport pathway of SH-EP from ER to protein storage vacuoles. A proform of SH-EP synthesized in ER accumulated at the edge or middle region of ER where the transport vesicle was formed. The vesicle containing a large amount of proSH-EP, termed KV, budded off from ER, bypassed the Golgi complex, and was sorted to protein storage vacuoles. This massive transport of SH-EP via KV was thought to mediate dynamic protein mobilization in the cotyledon cells of germinated seeds. We discuss the possibilities that the KDEL sequence of KDEL-tailed vacuolar cysteine proteinases function as an accumulation signal at ER, and that the mass transport of the proteinases by ER-derived KV-like vesicle is involved in the protein mobilization of plants.

Key Words: cysteine proteinase • endoplasmic reticulum • intracellular transport • KDEL sequence • protein storage vacuole

© 2000 The Rockefeller University Press

Abbreviations used in this paper: KV, KDEL-tailed cysteine proteinase-accumulating vesicle; PAC, precursor accumulating; PSV, protein storage vacuole; TB, toluidine blue.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?




  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents