A novel Rho-mDia2-HDAC6 pathway controls podosome patterning through microtubule acetylation in osteoclasts.
Osteoclast maturation is accompanied by changes in podosome patterning, resulting in the formation of a peripheral belt, which requires an intact microtubule network. Here, we report that by inhibiting Rho, the podosome belt is maintained at the cell periphery despite depolymerisation of microtubules by nocodazole. Rho inhibition was correlated to the increase in microtubule stabilisation and microtubule acetylation. By microinjecting activated Rho or its activated effector mDia2 in osteoclasts, we found that the podosome belt was disrupted and the level of microtubule acetylation dramatically decreased. We further characterised the molecular mechanism responsible for microtubule deacetylation by co-immunoprecipitation experiments. We found that not only was mDia2 coprecipitating with the recently identified microtubule deacetylase HDAC6 but that it also activated the microtubule deacetylase activity of HDAC6 in an in vitro deacetylase assay. Finally, we found that during osteoclastogenesis, there is a correlation between the increase in microtubule acetylation and the podosome belt stabilisation and that if Rho is inhibited in the early stages of osteoclast differentiation, it accelerates both microtubule acetylation and podosome belt stabilisation. Altogether, our data reveal a pathway in which Rho interferes with the osteoclast maturation process by controlling the level of microtubule acetylation and actin organisation through mDIA2 and HDAC6.
Laboratoire de Biologie Moléculaire et Cellulaire, UMR 5665 CNRS/ENS, INRA 913, Ecole Normale Supérieure de Lyon, 46, allée d'Italie, 69364 Lyon Cedex 7, France.
Olivier
O
Destaing
Frédéric
F
Saltel
Benoit
B
Gilquin
Anne
A
Chabadel
Saadi
S
Khochbin
Stéphane
S
Ory
Pierre
P
Jurdic
D000107:Acetylation; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism* / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D000080865:Formins; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D013154:Spleen / Q000166:cytology; D020741:rho GTP-Binding Proteins / Q000378:metabolism* / Q000494:pharmacology
D002352:Carrier Proteins; C491463:Diap2 protein, mouse; D000080865:Formins; C499033:Hdac6 protein, mouse; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases; D020741:rho GTP-Binding Proteins