GRIP1 and GRIP2 structure and characterization of GRIP1- and GRIP2-specific antibodies.a, Domain structure and sequence alignment of members of the GRIP protein family. GRIP2 is highly homologous to GRIP1, especially in the PDZ domains. ABP is a shorter splice variant of GRIP2, lacking the N-terminal sequence and the seventh PDZ domain. Regions of GRIP1 and GRIP2 used to generate GRIP-specific antibodies are indicated by the shaded bar. The region indicated between PDZ3 and PDZ4 of GRIP1 and GRIP2 is alternatively spliced. b, Brain lysates or HEK293T cells transfected with GRIP1 or GRIP2 were analyzed using the GRIP1-specific antibodies. c, Brain lysates or HEK293T cells transfected with GRIP1 or GRIP2 were analyzed using the GRIP2-specific antibodies. b, c, Preabsorption of both antibodies with the respective immunogenic peptides blocked immunorecognition.