5'-AMP-activated protein kinase subunit beta (IPR039160)

Short name: AMPKB

Overlapping homologous superfamilies

Family relationships



AMPK, a serine/threonine protein kinase (STK), catalyzes the transfer of the gamma-phosphoryl group from ATP to S/T residues on protein substrates. It acts as a sensor for the energy status of the cell and is activated by cellular stresses that lead to ATP depletion such as hypoxia, heat shock, and glucose deprivation, among others. AMPK is a heterotrimer of three subunits: alpha, beta, and gamma [PMID: 18855699]. The alpha subunit is the catalytic subunit and it contains an N-terminal kinase domain, a putative autoinhibitory domain (AID) and a C-terminal region required for beta subunit binding. The beta scaffolding subunit mediates AMPK assembly by bridging alpha and gamma subunits. The C-terminal domain of the AMPK alpha 1 subunit interacts with the C-terminal region of the beta subunit to form a tight alpha-beta complex that is associated with the gamma subunit. The AMPK alpha subunit auto-inhibitory region interacts with the kinase domain; this inhibition is negated by the interaction with the AMPK gamma subunit [PMID: 21481774].

AMPK has been implicated in a number of diseases related to energy metabolism including type 2 diabetes, obesity and cancer [PMID: 16753576, PMID: 19629071]. AMPK is activated by rising AMP concentrations coupled with falling ATP concentrations. Activation of AMPK is also dependent on the phosphorylation of alpha subunit by upstream kinases such as LKB1 [PMID: 14614828].

The beta subunit exists in two isoforms (beta-1 and beta-2). AMPK beta-1 is widely expressed whereas AMPK beta-2 is highly expressed in muscle, and both contain a carbohydrate-binding module (CBM) that interacts with glycogen [PMID: 20637197, PMID: 25774984].

GO terms

Biological Process

GO:0050790 regulation of catalytic activity

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.