EB1 and APC bind to mDia to stabilize microtubules downstream of Rho and promote cell migration.
Lysophosphatidic acid (LPA) stimulates Rho GTPase and its effector, the formin mDia, to capture and stabilize microtubules in fibroblasts. We investigated whether mammalian EB1 and adenomatous polyposis coli (APC) function downstream of Rho-mDia in microtubule stabilization. A carboxy-terminal APC-binding fragment of EB1 (EB1-C) functioned as a dominant-negative inhibitor of microtubule stabilization induced by LPA or active mDia. Knockdown of EB1 with small interfering RNAs also prevented microtubule stabilization. Expression of either full-length EB1 or APC, but not an APC-binding mutant of EB1, was sufficient to stabilize microtubules. Binding and localization studies showed that EB1, APC and mDia may form a complex at stable microtubule ends. Furthermore, EB1-C, but not an APC-binding mutant, inhibited fibroblast migration in an in vitro wounding assay. These results show an evolutionarily conserved pathway for microtubule capture, and suggest that mDia functions as a scaffold protein for EB1 and APC to stabilize microtubules and promote cell migration.
Department of Anatomy & Cell Biology, Columbia University, New York, NY 10032, USA.
Ying
Y
Wen
Christina H
CH
Eng
Jan
J
Schmoranzer
Noemi
N
Cabrera-Poch
Edward J S
EJ
Morris
Michael
M
Chen
Bradley J
BJ
Wallar
Arthur S
AS
Alberts
Gregg G
GG
Gundersen
D025601:Adenomatous Polyposis Coli Protein / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism* / Q000502:physiology; D002465:Cell Movement; D005347:Fibroblasts / Q000502:physiology; D000080865:Formins; D008246:Lysophospholipids / Q000494:pharmacology; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism* / Q000502:physiology; D008870:Microtubules / Q000378:metabolism*; D041681:NIH 3T3 Cells; D011485:Protein Binding; D014162:Transfection; D020741:rho GTP-Binding Proteins
D025601:Adenomatous Polyposis Coli Protein; D002352:Carrier Proteins; C491464:Diap1 protein, mouse; C405804:EB1 microtubule binding proteins; D000080865:Formins; D008246:Lysophospholipids; D008869:Microtubule-Associated Proteins; D020741:rho GTP-Binding Proteins; C032881:lysophosphatidic acid