Crystal structure of RIAM in an autoinhibited configuration.

Experimental Data Snapshot

  • Resolution: 2.40 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.211 
  • R-Value Observed: 0.213 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


Molecular basis for autoinhibition of RIAM regulated by FAK in integrin activation.

Chang, Y.C.Su, W.Cho, E.A.Zhang, H.Huang, Q.Philips, M.R.Wu, J.

(2019) Proc Natl Acad Sci U S A 116: 3524-3529

  • DOI: https://doi.org/10.1073/pnas.1818880116

  • PubMed Abstract: 

    RAP1-interacting adapter molecule (RIAM) mediates RAP1-induced integrin activation. The RAS-association (RA) segment of the RA-PH module of RIAM interacts with GTP-bound RAP1 and phosphoinositol 4,5 bisphosphate but this interaction is inhibited by the N-terminal segment of RIAM. Here we report the structural basis for the autoinhibition of RIAM by an intramolecular interaction between the IN region (aa 27-93) and the RA-PH module. We solved the crystal structure of IN-RA-PH to a resolution of 2.4-Å. The structure reveals that the IN segment associates with the RA segment and thereby suppresses RIAM:RAP1 association. This autoinhibitory configuration of RIAM can be released by phosphorylation at Tyr45 in the IN segment. Specific inhibitors of focal adhesion kinase (FAK) blocked phosphorylation of Tyr45, inhibited stimulated translocation of RIAM to the plasma membrane, and inhibited integrin-mediated cell adhesion in a Tyr45-dependent fashion. Our results reveal an unusual regulatory mechanism in small GTPase signaling by which the effector molecule is autoinhibited for GTPase interaction, and a modality of integrin activation at the level of RIAM through a FAK-mediated feedforward mechanism that involves reversal of autoinhibition by a tyrosine kinase associated with integrin signaling.

  • Organizational Affiliation

    Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, PA 19111.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Rap1-interacting adapter molecule359Mus musculusMutation(s): 0 
Gene Names: Apbb1ipmCG_15166RP23-114M13.3-001
UniProt & NIH Common Fund Data Resources
Find proteins for B1AYC9 (Mus musculus)
Explore B1AYC9 
Go to UniProtKB:  B1AYC9
IMPC:  MGI:1861354
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupB1AYC9
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.40 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.211 
  • R-Value Observed: 0.213 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 136.495α = 90
b = 83.956β = 91.08
c = 45.2γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM119560

Revision History  (Full details and data files)

  • Version 1.0: 2019-02-20
    Type: Initial release
  • Version 1.1: 2019-03-13
    Changes: Data collection, Database references
  • Version 1.2: 2020-01-01
    Changes: Author supporting evidence
  • Version 1.3: 2023-10-11
    Changes: Data collection, Database references, Refinement description