Structure of the Shroom-Rho Kinase Complex Reveals a Binding Interface with Monomeric Shroom That Regulates Cell Morphology and Stimulates Kinase Activity

J Biol Chem. 2016 Dec 2;291(49):25364-25374. doi: 10.1074/jbc.M116.738559. Epub 2016 Oct 10.


Shroom-mediated remodeling of the actomyosin cytoskeleton is a critical driver of cellular shape and tissue morphology that underlies the development of many tissues including the neural tube, eye, intestines, and vasculature. Shroom uses a conserved SD2 domain to direct the subcellular localization of Rho-associated kinase (Rock), which in turn drives changes in the cytoskeleton and cellular morphology through its ability to phosphorylate and activate non-muscle myosin II. Here, we present the structure of the human Shroom-Rock binding module, revealing an unexpected stoichiometry for Shroom in which two Shroom SD2 domains bind independent surfaces on Rock. Mutation of interfacial residues impaired Shroom-Rock binding in vitro and resulted in altered remodeling of the cytoskeleton and loss of Shroom-mediated changes in cellular morphology. Additionally, we provide the first direct evidence that Shroom can function as a Rock activator. These data provide molecular insight into the Shroom-Rock interface and demonstrate that Shroom directly participates in regulating cytoskeletal dynamics, adding to its known role in Rock localization.

Keywords: Ras homolog gene family, member A (RhoA); Rho-kinase; RhoA; Shroom; X-ray crystallography; coiled-coil; cytoskeleton; serine/threonine protein kinase; structural biology.

MeSH terms

  • G-Protein-Coupled Receptor Kinase 1 / chemistry*
  • G-Protein-Coupled Receptor Kinase 1 / genetics
  • G-Protein-Coupled Receptor Kinase 1 / metabolism
  • Humans
  • Membrane Proteins / chemistry*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Microfilament Proteins / chemistry*
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism
  • Multiprotein Complexes / chemistry*
  • Multiprotein Complexes / genetics
  • Multiprotein Complexes / metabolism
  • Myosin Type II / chemistry
  • Myosin Type II / genetics
  • Myosin Type II / metabolism
  • Protein Domains
  • Protein Structure, Quaternary
  • Structure-Activity Relationship


  • Membrane Proteins
  • Microfilament Proteins
  • Multiprotein Complexes
  • Shroom1 protein, human
  • G-Protein-Coupled Receptor Kinase 1
  • GRK1 protein, human
  • Myosin Type II

Associated data

  • PDB/5F4Y
  • PDB/5F5P
  • PDB/4L2W
  • PDB/3THF