5'-AMP-activated protein kinase subunit beta-1 (PRKAB1)

5'-AMP-activated protein kinase subunit beta-1 (PRKAB1) is a non-catalytic regulatory subunit of the heterotrimeric AMP-activated protein kinase (AMPK) complex, which functions as a central energy sensor in eukaryotic cells [1, 8]. It serves as a scaffold that bridges the catalytic alpha subunit and the regulatory gamma subunit, ensuring the stability and proper assembly of the enzyme complex [3, 16]. The beta-1 subunit contains a carbohydrate-binding module (CBM) that allows AMPK to sense cellular glycogen levels and serves as a site for allosteric activation by small molecules [2, 13]. In response to energy stress (low ATP), PRKAB1-containing AMPK complexes activate catabolic pathways like glucose uptake and fatty acid oxidation while inhibiting energy-consuming anabolic processes [10, 14]. This makes it a significant therapeutic target for metabolic diseases such as type 2 diabetes and obesity, as well as for cancer and neurodegenerative conditions [4, 15]. Pharmacological agents like salicylate and A-769662 directly bind to the beta-1 subunit to allosterically activate the complex, providing a mechanism for isoform-specific therapeutic intervention [7, 14].

Other names

AMPK beta-1PRKAB1HAMPKbProtein kinase AMP-activated non-catalytic subunit beta 1AMPK subunit beta-1

Drugs targeting the 5'-AMP-activated protein kinase subunit beta-1 primarily act through allosteric activation of the AMPK heterotrimer. Direct activators, such as A-769662 and salicylate, bind to the allosteric drug and metabolite (ADaM) site located between the alpha-subunit kinase domain and the beta-subunit carbohydrate-binding module (CBM), stabilizing the active conformation and protecting the complex from dephosphorylation [7, 13, 16]. Indirect activators like metformin work by inhibiting mitochondrial complex I, thereby increasing the cellular AMP:ATP ratio, which leads to the activation of AMPK complexes containing the beta-1 subunit [3, 11, 13].