TY - JOUR
T1 - RhoJ interacts with the GIT-PIX complex and regulates focal adhesion disassembly
AU - Wilson, Eleanor
AU - Leszczynska, Katarzyna
AU - Poulter, Natalie S.
AU - Edelmann, Francesca
AU - Salisbury, Victoria A.
AU - Noy, Peter J.
AU - Bacon, Andrea
AU - Rappoport, Joshua Z.
AU - Heath, John K.
AU - Bicknell, Roy
AU - Heath, Victoria L.
PY - 2014
Y1 - 2014
N2 - RhoJ is a Rho GTPase expressed in endothelial cells and tumour cells, which regulates cell motility, invasion, endothelial tube formation and focal adhesion numbers. This study aimed to further delineate the molecular function of RhoJ. Using timelapse microscopy RhoJ was found to regulate focal adhesion disassembly; small interfering RNA (siRNA)-mediated knockdown of RhoJ increased focal adhesion disassembly time, whereas expression of an active mutant (daRhoJ) decreased it. Furthermore, daRhoJ co-precipitated with the GIT-PIX complex, a regulator of focal adhesion disassembly. An interaction between daRhoJ and GIT1 was confirmed using yeast two-hybrid experiments, and this depended on the Spa homology domain of GIT1. GIT1, GIT2, b-PIX (also known as ARHGEF7) and RhoJ all colocalised in focal adhesions and depended on each other for their recruitment to focal adhesions. Functionally, the GIT-PIX complex regulated endothelial tube formation, with knockdown of both GIT1 and GIT2, or ß-PIX phenocopying RhoJ knockdown. RhoJ-knockout mice showed reduced tumour growth and diminished tumour vessel density, identifying a role for RhoJ in mediating tumour angiogenesis. These studies give new insight into the molecular function of RhoJ in regulating cell motility and tumour vessel formation.
AB - RhoJ is a Rho GTPase expressed in endothelial cells and tumour cells, which regulates cell motility, invasion, endothelial tube formation and focal adhesion numbers. This study aimed to further delineate the molecular function of RhoJ. Using timelapse microscopy RhoJ was found to regulate focal adhesion disassembly; small interfering RNA (siRNA)-mediated knockdown of RhoJ increased focal adhesion disassembly time, whereas expression of an active mutant (daRhoJ) decreased it. Furthermore, daRhoJ co-precipitated with the GIT-PIX complex, a regulator of focal adhesion disassembly. An interaction between daRhoJ and GIT1 was confirmed using yeast two-hybrid experiments, and this depended on the Spa homology domain of GIT1. GIT1, GIT2, b-PIX (also known as ARHGEF7) and RhoJ all colocalised in focal adhesions and depended on each other for their recruitment to focal adhesions. Functionally, the GIT-PIX complex regulated endothelial tube formation, with knockdown of both GIT1 and GIT2, or ß-PIX phenocopying RhoJ knockdown. RhoJ-knockout mice showed reduced tumour growth and diminished tumour vessel density, identifying a role for RhoJ in mediating tumour angiogenesis. These studies give new insight into the molecular function of RhoJ in regulating cell motility and tumour vessel formation.
KW - Angiogenesis
KW - Focal adhesion
KW - GIT
KW - PIX
KW - RhoJ
UR - http://www.scopus.com/inward/record.url?scp=84904279179&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84904279179&partnerID=8YFLogxK
U2 - 10.1242/jcs.140434
DO - 10.1242/jcs.140434
M3 - Article
C2 - 24928894
AN - SCOPUS:84904279179
SN - 0021-9533
VL - 127
SP - 3039
EP - 3051
JO - Journal of cell science
JF - Journal of cell science
IS - 14
ER -