Activated FGFR4 phosphorylates FRS2

FRS2 (also known as FRS alpha is activated through tyrosine phosphorylation catalyzed by the protein kinase domain of the activated FGFR. FRS2 contains four binding sites for the adaptor protein GRB2 at residues Y196, Y306, Y349 and Y392, and two binding sites for the protein tyrosine phosphatase PPTN11/SHP2 at residues Y436 and Y471. Different FGFR isoforms may generate different phosphorylation patterns on FRS2 leading to alternate downstream signaling.

FRS2（亦称FRS alpha）的激活通过由激活的FGFR蛋白激酶结构域催化的酪氨酸磷酸化实现。FRS2含有四个结合位点，分别位于Y196、Y306、Y349和Y392残基，以与适配蛋白GRB2结合；同时，它还含有两个结合位点，位于Y436和Y471残基，以与蛋白酪氨酸磷酸酶PPTN11/SHP2结合。不同的FGFR同型异构体可能在FRS2上产生不同的磷酸化模式，从而导致下游信号传导的异构化。