Multimodal regulation of myosin VI ensemble transport by cargo adaptor protein GIPC

Ashim Rai, Rachit Shrivastava, Duha Vang, Michael Ritt, Fredrik Sadler, Shreyas Bhaban, Murti Salapaka, Sivaraj Sivaramakrishnan

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

A range of cargo adaptor proteins are known to recruit cytoskeletal motors to distinct subcellular compartments. However, the structural impact of cargo recruitment on motor function is poorly understood. Here, we dissect the multimodal regulation of myosin VI activity through the cargo adaptor GAIP-interacting protein, C terminus (GIPC), whose overexpression with this motor in cancer enhances cell migration. Using a range of biophysical techniques, including motility assays, FRET-based conformational sensors, optical trapping, and DNA origami–based cargo scaffolds to probe the individual and ensemble properties of GIPC–myosin VI motility, we report that the GIPC myosin-interacting region (MIR) releases an autoinhibitory interaction within myosin VI. We show that the resulting conformational changes in the myosin lever arm, including the proximal tail domain, increase the flexibility of the adaptor–motor linkage, and that increased flexibility correlates with faster actomyosin association and dissociation rates. Taken together, the GIPC MIR–myosin VI interaction stimulates a twofold to threefold increase in ensemble cargo speed. Furthermore, the GIPC MIR–myosin VI ensembles yield similar cargo run lengths as forced processive myosin VI dimers. We conclude that the emergent behavior from these individual aspects of myosin regulation is the fast, processive, and smooth cargo transport on cellular actin networks. Our study delineates the multimodal regulation of myosin VI by the cargo adaptor GIPC, while highlighting linkage flexibility as a novel biophysical mechanism for modulating cellular cargo motility.

Original languageEnglish (US)
Article number101688
JournalJournal of Biological Chemistry
Volume298
Issue number3
DOIs
StatePublished - Mar 1 2022

Bibliographical note

Funding Information:
Acknowledgments—We acknowledge the University Imaging Centers, University of Minnesota, for their support and assistance with TIRF microscopy imaging and analysis. This work was supported by the resources and staff at the University of Minnesota University Imaging Centers (grant no.: SCR_020997).

Funding Information:
Funding and additional information—This work was supported by the National Institutes of Health (grant no.: R35GM126940; to S. S.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Funding Information:
We acknowledge the University Imaging Centers, University of Minnesota, for their support and assistance with TIRF microscopy imaging and analysis. This work was supported by the resources and staff at the University of Minnesota University Imaging Centers (grant no.: SCR_020997). Funding and additional information?This work was supported by the National Institutes of Health (grant no.: R35GM126940; to S. S.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Publisher Copyright:
© 2022 THE AUTHORS.

Fingerprint

Dive into the research topics of 'Multimodal regulation of myosin VI ensemble transport by cargo adaptor protein GIPC'. Together they form a unique fingerprint.

Cite this