Fig. 2

The PDZ-binding domain IQSEC2 isoform (NM_001111125.2 / NP_001104595.1) is the dominant form expressed specifically in brain. Expression of IQSEC2 isoforms across multiple tissues was quantified using two different methods. (a) Cap Analysis of Gene Expression (CAGE) data shows that the upstream transcription start site (P2), which gives rise only to NM_001111125.2/ENST00000396435.8, is strongly and specifically expressed in the brain while the downstream transcription start site (P1) is more broadly expressed across other tissues. Tissues were chosen based on relatively strong expression of any TSS and sample data, then grouped by tissue. (b) Isoform specific intron-spanning RNA-seq reads were quantified to show relative levels of isoform expression, again confirming that NM_001111125.2 is the dominant brain form. Between the two non-PDZ-binding domain forms (NM_001243197.1/ENST00000639161.1 and NM_015075.1/ENST00000375365.2) the shortest form NM_001243197.1 is the isoform predominantly expressed in nonneuronal tissues, and it is also weakly expressed in the brain. Tissues were chosen based on Fig. 2a, but are more limited due to data availability. All data are mean +/− SEM, individual sample data are provided in Table S3