The present invention concerns a method for identifying a compound which inhibits the activation of RAC GTPase by DOCK5 protein comprising the steps of (i) coexpressing the DOCK5 and the RAC proteins in a cell, wherein said DOCK5 protein induces the conversion of inactive RAC, which inactive RAC is bound to GDP, to active RAC, which active RAC is bound to GTP, (ii) contacting or not said cell with said compound, (iii) determining the conversion of inactive RAC to active RAC in the presence or absence of said compound, and (iv) selecting the compound inhibiting the conversion of inactive RAC to active RAC. Said compound is useful for treating disease-associated bone loss.
