A RhoC biosensor reveals differences in the activation kinetics of RhoA and RhoC in migrating cells.
RhoA and RhoC GTPases share 92% amino acid sequence identity, yet play different roles in regulating cell motility and morphology. To understand these differences, we developed and validated a biosensor of RhoC activation (RhoC FLARE). This was used together with a RhoA biosensor to compare the spatio-temporal dynamics of RhoA and RhoC activity during cell protrusion/retraction and macropinocytosis. Both GTPases were activated similarly at the cell edge, but in regions more distal from the edge RhoC showed higher activation during protrusion. The two isoforms differed markedly in the kinetics of activation. RhoC was activated concomitantly with RhoA at the cell edge, but distally, RhoC activation preceded RhoA activation, occurring before edge protrusion. During macropinocytosis, differences were observed during vesicle closure and in the area surrounding vesicle formation.
Department of Pharmacology and Lineberger Cancer Center, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America.
Jon S
JS
Zawistowski
Mohsen
M
Sabouri-Ghomi
Gaudenz
G
Danuser
Klaus M
KM
Hahn
Louis
L
Hodgson
D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002460:Cell Line; D006801:Humans; D007700:Kinetics; D051379:Mice; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*; D020743:rhoB GTP-Binding Protein / Q000378:metabolism*
D020742:rhoA GTP-Binding Protein; D020743:rhoB GTP-Binding Protein