Antigen-bearing MHC Class II : TCR complex:CD4:p-Lck(Y505) Antigen-bearing MHC Class II : TCR complex:CD4:Lck Dephosphorylation of Lck-pY505 by CD45 Authored: Rudd, C.E., de Bono, B, Garapati, P V, 2008-01-24 15:53:10 EC Number: 3.1.3.48 Pubmed11827988 Reactome Database ID Release 43202214 Reactome, http://www.reactome.org ReactomeREACT_12446 Reviewed: Trowsdale, J, 2008-02-26 12:02:59 TCR stimulation induce the transient dephosphorylation of PAG thereby release the Csk from its plasma membrane anchor. The release of Csk from its proximity with Lck may serve to facilitate the activation of Lck. The inactive Lck is dephosphorylated by CD45 phosphatase. CD45 specifically dephosphorylates the Y505 residue of Lck and induce the active open conformation.