Here, we describe how the hyperactivation of Rac1 via the P29S mutation (Rac1<sup>P29S</sup>) in melanoma hijacks branched actin network assembly to coordinate proliferative cues that facilitate metastasis and drug resistance.
A point mutation (P29S) in the RAS-related C3 botulinum toxin substrate 1 (RAC1) was considered to be a trigger for melanoma, a form of skin cancer with highest mortality rate.
RAC1 is a GTPase member of the RAS superfamily, and RAC1(P29S) was recently identified as the third most common recurrent mutation in melanomas, affecting 4-7% of the patients.
Conversely, RNAi-mediated silencing of endogenous RAC1 P29S in a melanoma cell line with a co-occurring BRAF V600 mutation increased sensitivity to vemurafenib and dabrafenib.