Evidence for posttranslational control of Hb C synthesis in an individual with Hb C trait and alpha-thalassemia.
The level of Hb C in the erythrocytes of individuals with Hb C trait decreases significantly in the presence of coexisting alpha-thalassemia. This relationship may result from the higher affinity of beta A than beta C for limiting amounts of alpha-globin during hemoglobin assembly. This mechanism would predict that the beta A and beta C synthetic capacity in alpha-thalassemic individuals with Hb C trait should be balanced despite the low levels of Hb C in their circulating erythrocytes. To directly test this prediction, we have measured the beta A and beta C synthetic capacity of reticulocyte RNA isolated from two individuals with Hb C trait, one with a normal alpha-globin genotype and one with alpha-thalassemia. The balanced expression of beta A and beta C in both cases supports the proposed posttranslational control over Hb C expression.
Liebhaber
S A
SA
Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6072.
Cash
F E
FE
Cornfield
D B
DB
D005786:Gene Expression Regulation; D005914:Globins / Q000235:genetics; D006444:Hemoglobin C / Q000235:genetics*; D006445:Hemoglobin C Disease / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D014176:Protein Biosynthesis; D012156:Reticulocytes / Q000502:physiology*; D013789:Thalassemia / Q000235:genetics*
D005914:Globins; D006444:Hemoglobin C