The present invention provides compositions and methods relating to or derived from antigen binding proteins capable of inducing B-Klotho, and or FGF21-like mediated signaling. In embodiments, the antigen binding proteins specifically bind to a complex comprising ²-Klotho and at least one of (i) FGFR1c, (ii) FGFR2c and (iii) FGFR3c. In some embodiments the antigen binding proteins induce FGF21-like signaling. In some embodiments, an antigen binding protein is a fully human, humanized, or chimeric antibodies, binding fragments and derivatives of such antibodies, and polypeptides that specifically bind to a complex comprising ²-Klotho and at least one of (i) FGFR1c, (ii) FGFR2c and (iii) FGFR3c. Other embodiments provide nucleic acids encoding such antigen binding proteins, and fragments and derivatives thereof, and polypeptides, cells comprising such polynucleotides, methods of making such antigen binding proteins, and fragments and derivatives thereof, and polypeptides, and methods of using such antigen binding proteins, fragments and derivatives thereof, and polypeptides, including methods of treating or diagnosing subjects suffering from type 2 diabetes, obesity, NASH, metabolic syndrome and related disorders or conditions.
