Direct Interaction between TalinB and Rap1 is necessary for adhesion of Dictyostelium cells. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Plak, Katarzyna; Pots, Henderikus; Van Haastert, Peter; Kortholt, Arjan
• Is Part Of: BMC cell biology. Volume 17:Issue 1(2016)
• Page Start: 1
• Page End: 8
• Publication Date: 2016-12
• Subjects: Rap -- talin -- Dictyostelium -- Adhesion -- Chemotaxis -- Development; Cytology -- Periodicals; 571.605
• DOI: 10.1186/s12860-015-0078-0
• Languages: English
• ISSNs: 1471-2121

Abstract

Abstract Background The small G-protein Rap1 is an important regulator of cellular adhesion inDictyostelium, however so far the downstream signalling pathways for cell adhesion are not completely characterized. In mammalian cells talin is crucial for adhesion and Rap1 was shown to be a key regulator of talin signalling. Results In a proteomic screen we identified TalinB as a potential Rap1 effector inDictyostelium . In subsequent pull-down experiments we demonstrate that the Ras association (RA) domain of TalinB interacts specifically with active Rap1. Studies with a mutated RA domain revealed that the RA domain is essential for TalinB-Rap1 interaction, and that this interaction contributes to cell-substrate adhesion during single-celled growth and is crucial for cell-cell adhesion during multicellular development. Conclusions Dictyostelium Rap1 directly binds to TalinB via the conserved RA domain. This interaction is critical for adhesion, which becomes essential for high adhesive force demanding processes, like morphogenesis during multicellular development ofDictyostelium . In mammalian cells the established Rap1-talin interaction is indirect and acts through the scaffold protein - RIAM. Interestingly, direct binding of mouse Rap1 to the RA domain of Talin1 has recently been demonstrated.