Chunk #18 — Results — Kal7 is expressed in the major neuronal cell types in nucleus accumbens and dorsal striatum — Usage of ΔKalrn promoter and alternate 3'-terminal exons is region-specific
Primers specific to the 3'-terminal exons unique to the different Kalrn isoforms (Figures 2, 4A) were used to look for differences between prefrontal cortex and nucleus accumbens (Figure 4C). Q-PCR analysis revealed much higher levels of transcripts encoding the Kal7-specific exon in prefrontal cortex than in nucleus accumbens. These transcripts could encode full-length Kal7 or ΔKal7. The Kal7-specific exon encodes a PDZ-binding domain known to interact with PSD-95 and spinophilin [18]. Transcripts encoding Kal8, Kal9 and Kal12 were detected at much lower levels in both tissues, with no tissue-specific differences. The isoforms of Kalirin that include both GEF1 and GEF2 (Kal9, Kal12) account for a larger fraction of the Kalirin transcripts in the nucleus accumbens than in the prefrontal cortex.
