1. Academic Validation
  2. The small molecule inhibitor NAV-2729 has a complex target profile including multiple ADP-ribosylation factor regulatory proteins

The small molecule inhibitor NAV-2729 has a complex target profile including multiple ADP-ribosylation factor regulatory proteins

  • J Biol Chem. 2023 Feb 7;102992. doi: 10.1016/j.jbc.2023.102992.
Eric M Rosenberg Jr 1 Xiaoying Jian 1 Olivier Soubias 2 Hye-Young Yoon 1 Mukesh P Yadav 1 Sarah Hammoudeh 1 Sandeep Pallikkuth 1 Itoro Akpan 1 Pei-Wen Chen 3 Tapan K Maity 4 Lisa M Jenkins 4 Marielle E Yohe 5 R Andrew Byrd 2 Paul A Randazzo 6
Affiliations

Affiliations

  • 1 Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute; Bethesda, MD, USA.
  • 2 Center for Structural Biology Laboratory, Center for Cancer Research, National Cancer Institute; Frederick, MD, USA.
  • 3 Department of Biology, Williams College; Williamstown, MA, USA.
  • 4 Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute; Bethesda, MD, USA.
  • 5 Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute; Bethesda, MD, USA; Laboratory of Cell and Developmental Signaling, Center for Cancer Research; Frederick, MD, USA.
  • 6 Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute; Bethesda, MD, USA. Electronic address: [email protected].
Abstract

The ADP-ribosylation factor (Arf)2 GTPases and their regulatory proteins are implicated in Cancer progression. NAV-2729 was previously identified as a specific inhibitor of Arf6 that reduced progression of uveal melanoma in an orthotopic xenograft. Here, our goal was to assess the inhibitory effects of NAV-2729 on the proliferation of additional cell types. We found NAV-2729 inhibited proliferation of multiple cell lines, but Arf6 expression did not correlate with NAV-2729 sensitivity, and knockdown of Arf6 affected neither cell viability nor sensitivity to NAV-2729. Furthermore, binding to native Arf6 was not detected; however, we determined that NAV-2729 inhibited both Arf exchange factors and Arf GTPase activating proteins (GAPs). ASAP1, a GAP linked to Cancer progression, was further investigated. We demonstrated that NAV-2729 bound to the PH domain of ASAP1 and changed ASAP1 cellular distribution. However, ASAP1 knockdown did not fully recapitulate the cytoskeletal effects of NAV-2729 nor affect cell proliferation. Finally, our screens identified 48 other possible targets of NAV-2729. These results illustrate the complexities of defining targets of small molecules and identify NAV-2729 as a model PH domain- binding inhibitor.

Keywords

ADP-ribosylation factor; ASAP1; GTPase; GTPase-activating protein; enzyme inhibitor; guanine nucleotide exchange factor.

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