Sequences of two isoforms of Arhgap39/Porf-2 protein in mouse. Sequences of two isoforms of Arhgap39/Porf-2 protein in mouse. The protein sequence numbers correspond to those in the NCBI database. Adapted from https://www.ncbi.nlm.nih.gov/gene/223666 (mouse). The functional domains include two WW, and one each of MyTH4 and GAP. Protein isoform 2 differs from isoform 1 in the deletion of 31 amino acids, encoded by exon 7, from the MyTH4 domain. Felicia V. Nowak eNeuro 2018;5:ENEURO.0082-18.2018 ©2018 by Society for Neuroscience