GDNF GI:40549413 glial cell derived neurotrophic factor isoform 3 1 mgcrgclpga aphrvrlpaa npensrgkgr rgqrgknrgc vltaihlnvt 50 51 dlglgyetke elifrycsgs cdaaettydk ilknlsrnrr lvsdkvgqac 100 101 crpiafdddl sflddnlvyh ilrkhsakrc gci