RGD Reference Report - Myosin 5a controls insulin granule recruitment during late-phase secretion. - Rat Genome Database

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Myosin 5a controls insulin granule recruitment during late-phase secretion.

Authors: Ivarsson, R  Jing, X  Waselle, L  Regazzi, R  Renstrom, E 
Citation: Ivarsson R, etal., Traffic. 2005 Nov;6(11):1027-35.
RGD ID: 1600832
Pubmed: (View Article at PubMed) PMID:16190983
DOI: Full-text: DOI:10.1111/j.1600-0854.2005.00342.x

We have examined the importance of the actin-based molecular motor myosin 5a for insulin granule transport and insulin secretion. Expression of myosin 5a was downregulated in clonal INS-1E cells using RNAinterference. Stimulated hormone secretion was reduced by 46% and single-cell exocytosis, measured by capacitance recordings, was inhibited by 42% after silencing. Silencing of Slac-2c/MYRIP, which links insulin granules to myosin 5a, resulted in similar inhibition of single-cell exocytosis. Antibody inhibition of the myosin 5a-Slac-2c/MYRIP interaction significantly reduced the recruitment of insulin granules for release. The pool of releasable granules independent of myosin 5a activity was estimated to approximately 550 granules. Total internal reflection microscopy was then applied to directly investigate granule recruitment to the plasma membrane. Silencing of myosin 5a inhibited granule recruitment during late phase of insulin secretion. In conclusion, we propose a model where insulin granules are transported through the actin network via both myosin 5a-mediated transport and via passive diffusion, with the former playing the major role during stimulatory conditions.


Gene Ontology Annotations    

Biological Process

Cellular Component
cytoplasm  (IDA)

Molecular Function

Objects Annotated

Genes (Rattus norvegicus)
Ins1  (insulin 1)
Myo5a  (myosin VA)

Additional Information