ERK5 is targeted to myocyte enhancer factor 2A (MEF2A) through a MAPK docking motif.
Barsyte-Lovejoy D, Galanis A, Clancy A, Sharrocks AD, Biochem J, 2004 Aug 1 - link

Docking domains and substrate-specificity determination for MAP kinases.
Sharrocks AD, Yang SH, Galanis A, Trends Biochem Sci, 2000 Sep - link