Activated FGFR2 binds FRS3

FRS3 (also known as FRS2beta) is predominantly expressed in the developing and adult neuroepithelium. As is the case for FRS2 (also known as FRS2alpha), binding of FRS3 to FGFR may be constitutive and/or independent of receptor activation. Elements of the downstream signaling mediated by the two FRS family members appear to be at least partially conserved, as FRS3 is phosphorylated upon FGF stimulation, binds PPTN11/SHP2 and GRB2 and results in ERK activation. Moreover, expression of FRS3 in FRS2-/- MEFs restores ERK activation.

FRS3（亦称FRS2beta）主要表达于发育期及成年的神经上皮组织中。与FRS2（亦称FRS2alpha）的情况相似，FRS3与FGFR的结合可能为构成性结合，亦或与受体激活无关。由FRS家族两位成员介导的下游信号传导途径的元素似至少部分保守，因为FRS3在FGF刺激下发生磷酸化，与PPTN11/SHP2和GRB2结合，并导致ERK的激活。此外，FRS3在FRS2-/- MEFs中的表达能够恢复ERK的激活。