The mouse Psma1 gene coding for the alpha-type C2 proteasome subunit: Structural and functional analysis. mapping, and colocalization with Pde3b on mouse chromosome 7

We have isolated and functionally characterized the mouse gene for the C2 s ubunit of the 20S proteasome. The gene contains 10 exons distributed over a region of 12 kb on the distal end of mouse chromosome 7. Its exon-intron s tructure differs from those of the other few known proteasome genes. Transf ection assays revealed that 1.5 kb of 5' flanking sequence is active as pro moter in cultured myoblasts. Deletion reporter constructs narrowed this pre sumptive promoter region to within 450 bp upstream of the translation initi ation site. Several consensus motifs for transcription factor binding sites were identified in this upstream region of the gene. Psma1 was mapped to m ouse chromosome 7 using the interspecific backcross DNA panels from The Jac kson Laboratory. Additional mapping studies showed that the mouse genes Psm a1 and Pde3b are closely linked, residing between cM 53 and 53.3 in a regio n syntenic to human chromosome 11p15. Our results extend the structural and functional analysis of genes encoding the 20S proteasome subunits and prov ide the basis For the study of their regulation, (C) 2000 Academic Press.