Submitted to: Genbank
Publication Type: Abstract Only
Publication Acceptance Date: 5/17/2006
Publication Date: 6/26/2006
Citation: Proszkowiec-Weglarz, M., Richards, M.P., Poch, S.M. 2006. Gallus gallus 5'-AMP-activated protein kinase beta-2 non-catalytic subunit transcript variant 1 (PRKAB2) mRNA, complete cds. GenBank Acession Number DQ640760.
Technical Abstract: AMP-activated protein kinase (AMPK) is a sensor of cellular energy charge. Once activated by an increase in the AMP:ATP ratio, AMPK acts as a master switch to increase energy-generating and to reduce energy-consuming metabolic pathways. AMPK exists as an enzyme complex consisting of one catalytic subunit (alpha) and two regulatory subunits (beta and gamma). A molecular cloning strategy involving primer-directed reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of 5' cDNA ends (5' RACE) was developed to initially sequence 1671 base pairs (bp) of a chicken skeletal muscle–derived cDNA corresponding to the complete coding region and portions of the 5'- and 3'-untranslated regions of the chicken AMPK beta-2 mRNA transcript variant 1. In fact, in-depth sequence analysis of 5' RACE and cloned PCR products indicated that four distinct transcript variants are produced form the chicken AMPK beta-2 gene that differ at their 5' ends due to alternate promoter usage and alternative splicing of exon 2. The chicken AMPK beta-2 transcript variant 1 mRNA codes for a predicted 272 amino acid protein which contains a glycogen binding domain (GBD) and an alpha/gamma interacting domain (ID). Further analysis of the AMPK beta-2 gene sequence revealed the occurrence of alternative splicing sites at the 3' end of exon 5 that cause an additional modification of transcript variant 1 in skeletal muscle. This modified transcript variant contains an extra 6 nucleotides at the 3'-end of exon 5 and codes for a predicted 274 amino acid protein that contains two additional amino acids located in a region of the protein between the GBD and ID. However, the modified transcript variant 1 is not highly expressed in skeletal muscle tissue and the unmodified form is predominant. This sequence data confirmed for the first time the existence and expression of the AMPK beta-2 transcript variant 1 mRNA in chickens. Such data will be useful in studying the structure and expression of the chicken AMPK beta-2 gene, as well as, in further defining the function of the AMPK pathway in poultry.