Structure of TBC1D23 N-terminus reveals a novel role for rhodanese domain

PLoS Biol. 2020 May 26;18(5):e3000746. doi: 10.1371/journal.pbio.3000746. eCollection 2020 May.

Abstract

Members of the Tre2-Bub2-Cdc16 (TBC) family often function to regulate membrane trafficking and to control signaling transductions pathways. As a member of the TBC family, TBC1D23 is critical for endosome-to-Golgi cargo trafficking by serving as a bridge between Golgi-bound golgin-97/245 and the WASH/FAM21 complex on endosomal vesicles. However, the exact mechanisms by which TBC1D23 regulates cargo transport are poorly understood. Here, we present the crystal structure of the N-terminus of TBC1D23 (D23N), which consists of both the TBC and rhodanese domains. We show that the rhodanese domain is unlikely to be an active sulfurtransferase or phosphatase, despite containing a putative catalytic site. Instead, it packs against the TBC domain and forms part of the platform to interact with golgin-97/245. Using the zebrafish model, we show that impacting golgin-97/245-binding, but not the putative catalytic site, impairs neuronal growth and brain development. Altogether, our studies provide structural and functional insights into an essential protein that is required for organelle-specific trafficking and brain development.

Publication types

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

MeSH terms

  • ADP-Ribosylation Factors / metabolism
  • Animals
  • Autoantigens / metabolism*
  • Brain / embryology*
  • Escherichia coli
  • GTPase-Activating Proteins / chemistry
  • GTPase-Activating Proteins / isolation & purification
  • GTPase-Activating Proteins / metabolism*
  • Golgi Matrix Proteins / metabolism*
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Membrane Proteins / metabolism
  • Protein Conformation
  • Protein Domains
  • Thiosulfate Sulfurtransferase / metabolism*
  • Zebrafish

Substances

  • Autoantigens
  • GTPase-Activating Proteins
  • Golgi Matrix Proteins
  • Golgi complex autoantigen, 97-kDa
  • Membrane Proteins
  • TBC1D23 protein, human
  • Thiosulfate Sulfurtransferase
  • ADP-ribosylation factor related proteins
  • ADP-Ribosylation Factors