Regulated nuclear polyadenylation of Xenopus albumin pre-mRNA.
Cytoplasmic regulation of the length of poly(A) on mRNA is a well-characterized process involved in translational control during development. In contrast, there is no direct in vivo evidence for regulation of the length of poly(A) added during nuclear pre-mRNA processing in somatic cells. We previously reported that Xenopus serum albumin [Schoenberg et al. (1989) Mol. Endocrinol. 3, 805-815] and transferrin [Pastori et al. (1992) J. Steroid Biochem. Mol. Biol. 42, 649-657], mRNA have exceptionally short poly(A) tails ranging from 12 to 17 residues, whereas vitellogenin mRNA has long poly(A). An RT-PCR protocol was adapted to determine the length of poly(A) added onto pre-mRNA, defined here as that species bearing the terminal intron. Using this assay we show that vitellogenin pre-mRNA has the same long poly(A) tail as mature vitellogenin mRNA. In contrast, albumin pre-mRNA has the same short poly(A) as found on fully-processed albumin mRNA. These results indicate that the short poly(A) tail on albumin mRNA results from regulation of poly(A) addition during nuclear 3' processing.
Rao
M N
MN
Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799, USA.
Chernokalskaya
E
E
Schoenberg
D R
DR
D000818:Animals; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D008099:Liver / Q000737:chemistry; D011061:Poly A / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012322:RNA Precursors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D012709:Serum Albumin / Q000235:genetics*; D014819:Vitellogenins / Q000235:genetics; D014981:Xenopus
D017931:DNA Primers; D012322:RNA Precursors; D012333:RNA, Messenger; D012709:Serum Albumin; D014819:Vitellogenins; D011061:Poly A