Alternative polyadenylation generates three low-pI alpha-amylase mRNAs with differential expression in barley.
Specific low-pI alpha-amylase genes from barley (Hordeum vulgare L.) produced alternative mRNAs with a 17-base 3' extension (extension 1) or a 17-base extension beyond this (extension 2). The extended mRNAs do not arise from splicing of downstream sequences, and not all low-pI genes contain the extended sequences. All three mRNAs occur in aleurones and shoots, while extension 2 is missing from scutella. Also, the unextended mRNAs predominate in total mRNA, but the extended mRNAs predominate in membrane-bound polysomes. The extended sequences do not occur in previously characterized alpha-amylases, but 16 of 18 bases, mainly in extension 1, are identical with a sequence in the 3'-UTR of PAPI, a putative inhibitor of alpha-amylase. These observations suggest that the extended sequences could play a functional role in alpha-amylase expression.
Skadsen
R W
RW
United States Department of Agriculture, Agricultural Research Service, Madison, WI 53705.
Knauer
N S
NS
D017398:Alternative Splicing; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary; D015870:Gene Expression; D015971:Gene Expression Regulation, Enzymologic; D017343:Genes, Plant; D001467:Hordeum / Q000201:enzymology* / Q000235:genetics; D007700:Kinetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid; D000516:alpha-Amylases / Q000096:biosynthesis* / Q000378:metabolism
D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D000516:alpha-Amylases