Unstable beta-globin mRNA in mRNA-deficient beta o thalassemia.
The molecular defect in four Kurdish Jews with homozygous, mRNA-deficient beta zero thalassemia was investigated. Electrophoretic profiles of pulse-labeled alpha- and beta-globin RNAs are similar to those of non-thalassemics; therefore, at least one of the thalassemic beta-globin alleles is transcribed. During a 30 min actinomycin D chase, most of the alpha- and beta-globin mRNA precursors and processing intermediates are converted to mRNA-sized RNA. Thalassemic and non-thalassemic beta-globin RNAs are indistinguishable, as determined by S1 nuclease mapping and RNA blotting. Non-thalassemic beta-globin mRNA is stable during a 30 min actinomycin chase, but 30%-75% of the thalassemic mRNA-sized molecules is degraded during that period. We conclude that the absence of beta-globin mRNA in this disease results from rapid turnover of beta-globin mRNA-sized molecules.
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D005914:Globins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008297:Male; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D017086:beta-Thalassemia / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D005914:Globins