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. 1993 Jul;4(7):747-56.
doi: 10.1091/mbc.4.7.747.

A rab protein regulates the localization of secretory granules in AtT-20 cells

J K Ngsee  1 , A M Fleming, R H Scheller
Affiliations
Free PMC article

A rab protein regulates the localization of secretory granules in AtT-20 cells

J K Ngsee et al. Mol Biol Cell. 1993 Jul.
Free PMC article

Abstract

Low molecular weight (LMW) GTP-binding proteins are hypothesized to play a role in the vectorial transport of intracellular vesicles. Mutational studies in yeast and subcellular localization in mammalian cells suggest that a family of LMW GTP-binding proteins, termed rab, target intracellular vesicles to their appropriate acceptor compartment. In this report, we demonstrate that an elasmobranch homologue of rab3A, o-rab3, plays a significant role in the sequestration of regulated secretory vesicles. When transfected into the murine endocrine cell line AtT-20, the wild-type o-rab3 protein is localized exclusively to the tips of the processes, a region of the cell known to accumulate proteins associated with regulated secretory vesicles. Two mutations, Gln81 to Leu (Q81L) and Asn135 Ile (N135I), which alter GTP binding or rate of hydrolysis, blocked the localization of the o-rab3 protein to the tips of cell processes. These mutations also hindered the sequestration of ACTH-containing secretory vesicles to the process tips but did not affect the basal or stimulated release of ACTH. Moreover, the sequestration of the protein VAMP to the process tip was also hindered by the mutation. The results demonstrate a role for the rab3 proteins in localization, sequestration, and storage of secretory vesicles near their release site.

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References

    1. J Biol Chem. 1992 Jun 15;267(17):11681-4 - PubMed
    1. Proc Natl Acad Sci U S A. 1992 Apr 15;89(8):3649-53 - PubMed
    1. J Biol Chem. 1992 Dec 5;267(34):24363-8 - PubMed
    1. J Neurochem. 1993 Mar;60(3):851-7 - PubMed
    1. Nature. 1993 Apr 8;362(6420):560-3 - PubMed

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