PTPN7 (HePTP) protein tyrosine phosphatase binds to MAPK1 (ERK2) (Saxena et al. 1999, Munoz et al. 2003) and MAPK3 (ERK1) (Oh-hora et al. 1999, Munoz et al. 2003). The interaction of PTPN7 with MAPKs involves the KIM (kinase-interaction motif) of PTPN7.
PTPN7 may have a preference for ERK2 over ERK1 (Pettiford and Herbst 2000). ERK1 used in the study by Oh-hora et al. 1999 was likely human, but it is not certain. In the study by Munoz et al. 2003, interaction of PTPN7 with rat ERK1 was demonstrated, but the origin of PTPN7 was not specified.