Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published September 8, 2022 | Submitted
Report Open

An extracellular vesicle targeting ligand that binds to Arc proteins and facilitates Arc transport in vivo


Communication between distant cells can be mediated by extracellular vesicles (EVs) that deliver proteins and RNAs to recipient cells. Little is known about how EVs are targeted to specific cell types. Here we identify the Drosophila cell-surface protein Stranded at second (Sas) as a targeting ligand for EVs. Full-length Sas is present in EV preparations from transfected Drosophila Schneider 2 (S2 cells). Sas is a binding partner for the Ptp10D receptor tyrosine phosphatase, and Sas-bearing EVs preferentially target to cells expressing Ptp10D. We used co-immunoprecipitation and peptide binding to show that the cytoplasmic domain (ICD) of Sas binds to dArc1. dArc1 and mammalian Arc are related to retrotransposon Gag proteins. They form virus-like capsids which encapsulate Arc and other mRNAs and are transported between cells via EVs. The Sas ICD contains a motif required for dArc1 binding that is shared by the mammalian and Drosophila amyloid precursor protein (APP) orthologs, and the Sas and APP ICDs also bind to mammalian Arc. Sas facilitates delivery of dArc1 capsids bearing dArc1 mRNA into distant Ptp10D-expressing recipient cells in vivo.

Additional Information

The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license. Mass spectrometry work was performed at the Caltech Proteome Exploration Laboratory. Imaging was done at the Caltech Biological Imaging facility. EM work was done at the Caltech Cryo-EM facility. We thank Andre Malyutin for negative stain EM. We thank Violana Nesterova for figure preparation. We thank the following colleagues for reagents and Drosophila lines: Jason Shepherd (University of Utah) for pGEX-dArc and rArc constructs; Travis Thomson and Vivian Budnik (University of Massachusetts) for rabbit anti-Arc1; Douglas Cavener (Penn State) for rabbit anti-SasFL; Deborah Andrew (Johns Hopkins) for Sage-GAL4; James Skeath (Washington University) for guinea pig anti-Numb; Swati Banerjee (UTHSC, San Antonio) for rat anti-Repo, and Yuh-Nung Jan (UCSF) for UAS-Numb. We thank Simon Erlendsson, Fernando Bazan, Paul Worley, and Tino Pleiner for discussions about Arc purification and Arc and Sas structures. This work was supported by NIH RO1 grants NS28182 and NS096509 to K.Z., and by Howard Hughes Medical Institute support to R. Deshaies, who was J.M.R.'s faculty supervisor when he was a postdoctoral fellow at Caltech. Author Contributions. P. H. L. designed and performed the majority of the experiments. M.A. helped with protein biochemistry work. M.S.L. performed the immuno-EM and EM tomography experiments. J.M.R. performed the mass spectrometry analysis of V5 IPs from EVs. P. H. L. and K.Z. wrote the manuscript. K.Z. directed the project. Competing Interest Statement. Justin M. Reitsma is affiliated with AbbVie. The author has no other competing interests to declare.

Attached Files

Submitted - 2022.09.06.506798v1.full.pdf


Files (27.0 MB)
Name Size Download all
27.0 MB Preview Download

Additional details

August 20, 2023
December 13, 2023