Characterization of the equine glycogen debranching enzyme gene (AGL): Genomic and cDNA structure, localization, polymorphism and expression.
Glycogen debranching enzyme (AGL) is a multifunctional enzyme acting in the glycogen degradation pathway. In humans, the AGL activity deficiency causes a type III glycogen storage disease (Cori-Forbes disease). One particularity of AGL gene expression lies in the multiple alternative splicing in its 5' region. The AGL gene was localized on ECA5q14-q15. The sequence of the equine cDNA was determined to be 7.5 kb in length with an open reading frame of 4602 bp. The gene is 69 kb long and contains 35 exons. The equine AGL gene has an ubiquitous expression and presents five tissue-dependent cDNA variants arising from alternative splicing of the first exons. The equine skeletal muscle and heart contain four out of six variants previously described in humans and the equine liver express three of these four human variants. We identified a new alternative splicing variant expressed in equine skeletal and heart muscles. All these mRNA variants most probably encode only two different protein isoforms of 1533 and 1377 amino-acids. Four SNPs were detected in the mRNA. The equine in silico promoter sequence reveals a structure similar to those of other mammalian species. The disposition of the transcription factor biding sites does not correlate to the transcription start sites of tissue-specific variants.
Herszberg
Bérénice
B
Institut National de la Recherche Agronomique, UR339, Centre de Recherches de Jouy, Laboratoire de Génétique biochimique et de Cytogénétique, 78350 Jouy-en-Josas, France.
Mata
Xavier
X
Giulotto
Elena
E
Decaunes
Pauline
P
Piras
Francesca M
FM
Chowdhary
Bhanu P
BP
Chaffaux
Stéphane
S
Guérin
Gérard
G
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression; D023281:Genomics; D006004:Glycogen Debranching Enzyme System / Q000235:genetics* / Q000378:metabolism; D006736:Horses / Q000235:genetics*; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D016415:Sequence Alignment; D014018:Tissue Distribution
D018076:DNA, Complementary; D006004:Glycogen Debranching Enzyme System; D012333:RNA, Messenger