Fyn binds NCAM1

Fyn constitutively associates with the 140 kD isoform of NCAM1 in the plasma membrane, probably indirectly. Fyn is attached to the lipid raft membrane compartment via palmitoylation and is inactivated by tyrosine phosphorylation (Y531) within its C-terminal regulatory region. Fyn kinase has two well-known phosphorylation sites which affect its activity in opposite ways. The phosphorylation of Tyr531 located in the C-terminus of the protein inhibits the Fyn kinase activity, due to the binding of this tyrosine residue to the SH2 domain of the protein, which stabilizes its catalytically inactive conformation.

Fyn与140 kD的NCAM1亚型在质膜中构成性结合，可能为间接结合。Fyn通过棕榈酰化附着于脂筏膜区室，并在其C端调控区域内通过酪氨酸磷酸化（Y531）失活。Fyn激酶具有两个已知的磷酸化位点，它们以相反的方式影响其活性。位于蛋白C端的酪氨酸531位的磷酸化会抑制Fyn激酶的活性，这是因为该酪氨酸残基与蛋白的SH2结构域结合，从而稳定了其催化非活性构象。