CHARACTERIZATION OF AMP-ACTIVATED PROTEIN KINASE BETA AND GAMMA SUBUNITS: ASSEMBLY OF THE HETEROTRIMERIC COMPLEX IN VITRO

摘要: There is growing evidence that mammalian AMP-activated protein kinase (AMPK) plays a role in protecting cells from stresses cause ATP depletion by switching off ATP-consuming biosynthetic pathways. The active form of AMPK rat liver exists as heterotrimeric complex and we have previously shown the catalytic subunit structurally functionally related to SNF1 Saccharomyces cerevisiae. Here describe isolation characterization two other polypeptides, termed AMPKbeta AMPKgamma, together with (AMPKalpha) liver. Sequence analysis cDNA clones encoding these subunits reveals they are yeast proteins interact SNF1, providing further regulation function been conserved throughout evolution. amino acid sequence beta most closely SIP2 (35% identity), while gamma 35% identical SNF4. We show both AMPKgamma mRNA expressed widely tissues. interacts AMPKalpha vitro, whereas does not under same conditions. These results suggest mediates association will facilitate future studies aimed at investigating vivo.