A campaign targeting a conserved Hsp70 binding site uncovers how subcellular localization is linked to distinct biological activities

Hao Shao; Shuhei Taguwa; Luke Gilbert; Arielle Shkedi; Sara Sannino; Christopher J Guerriero; Zachary J Gale-Day; Zapporah T Young; Jeffrey L Brodsky; Jonathan Weissman; Jason E Gestwicki; Judith Frydman

doi:10.1016/j.chembiol.2022.06.006

A campaign targeting a conserved Hsp70 binding site uncovers how subcellular localization is linked to distinct biological activities

Cell Chem Biol. 2022 Aug 18;29(8):1303-1316.e3. doi: 10.1016/j.chembiol.2022.06.006. Epub 2022 Jul 12.

Authors

Affiliations

¹ Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; College of Pharmaceutical Sciences, Southwest University, Chongqing 400716, China.
² Department of Biology, Stanford University, Stanford, CA 94305, USA; Laboratory of Virus Control, Center for Infectious Disease Education and Research, Osaka University, Osaka, Japan; Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
³ Department of Urology and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA.
⁴ Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA.
⁵ Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
⁶ Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA.
⁷ Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA. Electronic address: jason.gestwicki@ucsf.edu.
⁸ Department of Biology, Stanford University, Stanford, CA 94305, USA. Electronic address: jfrydman@stanford.edu.

Abstract

The potential of small molecules to localize within subcellular compartments is rarely explored. To probe this question, we measured the localization of Hsp70 inhibitors using fluorescence microscopy. We found that even closely related analogs had dramatically different distributions, with some residing predominantly in the mitochondria and others in the ER. CRISPRi screens supported this idea, showing that different compounds had distinct chemogenetic interactions with Hsp70s of the ER (HSPA5/BiP) and mitochondria (HSPA9/mortalin) and their co-chaperones. Moreover, localization seemed to determine function, even for molecules with conserved binding sites. Compounds with distinct partitioning have distinct anti-proliferative activity in breast cancer cells compared with anti-viral activity in cellular models of Dengue virus replication, likely because different sets of Hsp70s are required in these processes. These findings highlight the contributions of subcellular partitioning and chemogenetic interactions to small molecule activity, features that are rarely explored during medicinal chemistry campaigns.

Keywords: Hsp70; allosteric inhibitors; anti-cancer; antivirals; chaperones; chemical biology; subcellular localization.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Binding Sites
Endoplasmic Reticulum Chaperone BiP
HSP70 Heat-Shock Proteins* / metabolism
Molecular Chaperones* / metabolism
Protein Domains

Substances

Endoplasmic Reticulum Chaperone BiP
HSP70 Heat-Shock Proteins
Molecular Chaperones

Abstract

Publication types

MeSH terms

Substances

Grants and funding