Woods A, Salt I, Scott J, Hardie D G, Carling D
MRC Molecular Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
FEBS Lett. 1996 Nov 18;397(2-3):347-51. doi: 10.1016/s0014-5793(96)01209-4.
The AMP-activated protein kinase (AMPK) is a heterotrimeric complex composed of a catalytic subunit (alpha) and two regulatory subunits (beta and gamma). Two isoforms of the catalytic subunit (alpha1 and alpha2) have been identified. We show here that the alpha1- and alpha2-containing complexes contribute approximately equally to total AMPK activity in rat liver. Furthermore, expression of alpha1 or alpha2 with beta and gamma in mammalian cells demonstrates that both complexes have equal specific activity measured with the SAMS peptide. Using variant peptides, however, we show that alpha1 and alpha2 exhibit slightly different substrate preferences, which suggest that the two isoforms could play different physiological roles within the cell.
AMP 激活的蛋白激酶（AMPK）是一种异源三聚体复合物，由一个催化亚基（α）和两个调节亚基（β和γ）组成。已鉴定出催化亚基的两种同工型（α1和α2）。我们在此表明，含α1和α2的复合物对大鼠肝脏中的总 AMPK 活性贡献大致相等。此外，在哺乳动物细胞中α1或α2与β和γ的表达表明，用 SAMS 肽测量时，两种复合物具有相同的比活性。然而，使用变异肽时，我们表明α1和α2表现出略有不同的底物偏好，这表明这两种同工型可能在细胞内发挥不同的生理作用。
