Activity evaluation study of a mutational c-Src in NIH-3T3 cells

Abstract

Cancers can be caused by oncogenes, and c-Src is one of the most common proto-oncogenes; it is observed in 40% of cancers. Activated c-Src contributes to cancer cell growth and invasion through structures known as “invadopodia”. To be activated, several residues in c-Src must undergo phosphorylation changes. Tyr416 and Tyr527 are important in this respect, and each residue acts as a positive or negative regulator. Replacing Tyr416 with Phe416 (Y416F, YF) results in c-SRC being continuously activated so that it acts like an oncogene. However, it is unclear which residue plays a pivotal role in the conformational change of c-Src. Recently, one paper reported on several simulations indicated that a mutation of Lys321 to Ala321 (K321A, KA) can lead to an imperfect conformational change of c-Src; however, it is unclear whether this works at the cellular level. We made KA-substituted c-Src DNAs and found that these mutants cause variation of the phosphorylation state, decrease migration, and inhibit invadopodia formation when transfected to NIH-3T3 mouse fibroblasts. From these results, we anticipate that the K321 residue might be used to find novel c-Src-related cancer therapies.