We have previously shown that excess unpaired alpha- and beta-globin chains in severe alpha- and beta-thalassemia interacting with the membrane skeleton induce different changes in membrane properties of red blood cells (RBCs) in these two phenotypes. We suggest that these differences in membrane material behavior may reflect the specificity of the membrane damage induced by alpha- and beta-glo...

This investigation was designed to define the cellular level at which the gamma to beta globin switch is established in the developing simian fetus in order to determine whether the switch is controlled by environmental influences within differentiating erythroid precursors or predetermined by the genetic program of erythroid progenitors. Samples of marrow and liver were obtained from rhesus fe...

The Krüppel-like factors (KLFs) are a family of C2/H2 zinc finger DNA-binding proteins that are important in controlling developmental programs. Erythroid Krüppel-like factor (EKLF or KLF1) positively regulates the beta-globin gene in definitive erythroid cells. KLF2 (LKLF) is closely related to EKLF and is expressed in erythroid cells. KLF2-/- mice die between embryonic day 12.5 (E12.5) and E1...

In one form of beta-thalassemia, a genetic blood disorder, a mutation in intron 2 of the beta-globin gene (IVS2-654) causes aberrant splicing of beta-globin pre-mRNA and, consequently, beta-globin deficiency. Treatment of mammalian cells stably expressing the IVS2-654 human beta-globin gene with antisense oligonucleotides targeted at the aberrant splice sites restored correct splicing in a dose...

Results of electrophoretic surveys have suggested that hemoglobin polymorphism may be maintained by balancing selection in natural populations of house mice, Mus musculus. Here we report a survey of nucleotide variation in the adult globin genes of house mice from South America. We surveyed nucleotide polymorphism in two closely linked alpha-globin paralogs and two closely linked beta-globin pa...

There is decreased beta-globin production in beta-thalassemic reticulocytes and nucleated erythroid cells. In this study, we have examined whether unbalanced globin synthesis is expressed at all stages of human erythroid cell maturation. In order to determine the pattern of globin synthesis in early erythroid cells during erythroid cell maturation, an in vitro culture system using human bone ma...

Cryptic splice sites are used only when use of a natural splice site is disrupted by mutation. To determine the features that distinguish authentic from cryptic 5' splice sites (5'ss), we systematically analyzed a set of 76 cryptic 5'ss derived from 46 human genes. These cryptic 5'ss have a similar frequency distribution in exons and introns, and are usually located close to the authentic 5'ss....

The in vitro interaction of recombinant hnRNP A1 with purified snRNPs and with pre-mRNAs was investigated. We show that protein A1 can stably bind U2 and U4 snRNP but not U1. Oligo-RNAse H cleavage of U2 nucleotides involved in base pairing with the branch site, totally eliminates the A1-U2 interaction. RNase T1 protection and immunoprecipitation experiments demonstrate that recombinant protein...