A second, elongated, alpha 2-globin mRNA is present in reticulocytes from normal persons and subjects with terminating codon or poly A mutations.
With an RT-PCR procedure we have identified a second, elongated, alpha 2-globin mRNA in reticulocytes of normal persons and of patients with alpha-thal, particularly those with mutations in the terminating codon (TAA-->CAA; Hb Constant Spring; TAA-->TAT, Hb Paksé) or in the poly A site (AATAAA-->AATAAG). This type of mRNA is elongated because a result a cryptic poly A site 1048 bp past the terminating codon is used. Even some 5% of the alpha 2-mRNA of normal persons is of the elongated type. Quantitative data suggest high levels of this mRNA in heterozygous and homozygous carriers of poly A mutations and low levels in patients with the terminating codon mutations. Hematological and Hb data suggest that translation of these elongated mRNAs is minimal. No elongated alpha 1-mRNA has been observed.
Molchanova
T P
TP
Laboratory of Protein Chemistry, Medical College of Georgia, Augusta 30912-2100, USA.
Smetanina
N S
NS
Huisman
T H
TH
D001483:Base Sequence; D003062:Codon; D017931:DNA Primers; D006580:Genetic Carrier Screening; D005914:Globins / Q000096:biosynthesis* / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D008969:Molecular Sequence Data; D017354:Point Mutation; D011061:Poly A; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D012016:Reference Values; D012156:Reticulocytes / Q000378:metabolism*
D003062:Codon; D017931:DNA Primers; D012333:RNA, Messenger; D011061:Poly A; D005914:Globins