The residue at position 5 of the N-terminal region of Src and Fyn modulates their myristoylation, palmitoylation, and membrane interactions.

The interactions of Src family kinases (SFKs) with the plasma membrane are crucial for their activity. They depend on their fatty-acylated N-termini, containing N-myristate and either a polybasic cluster (in Src) or palmitoylation sites (e.g.

Src-mediated caveolin-1 phosphorylation affects the targeting of active Src to specific membrane sites.

Src interactions with the plasma membrane are an important determinant of its activity. In turn, Src activity modulates its association with the membrane through binding of activated Src to phosphotyrosylated proteins. Caveolin-1 (Cav-1), a major component of caveolae, is a known Src phosphorylation target, and both were reported to regulate cell transformation.