Molecular analysis of the mouse class II gene, E q alpha.

The structure and transcription of the mouse E q alpha gene were investigated by structural analysis of genomic clones, transient and stable cell line transformation, and spleen cell nuclear transcription studies. The transcription rate of Eq alpha is comparable to that of the Ek alpha allele. The q allele is transcribed to a normal size mRNA, but the Eq alpha mRNA level in spleen cells is 100-fold less than that of Ek alpha and is increased after cycloheximide treatment. The promoter region of the q allele can stimulate transcription of the chloramphenicol acetyl transferase gene after treatment with gamma interferon in transient expression assays. The Eq alpha gene was cloned and sequenced from -1630 nucleotide to +5200 nucleotide, and it shows 98% sequence identity with Eq alpha. A frame shift in codon 89 causes premature termination of translation, which probably accounts for its low steady state level of mRNA.