Receptor for activated C kinase 1 (RACK1)

Receptor for activated C kinase 1 (RACK1) is a conserved intracellular scaffold protein comprising seven WD40 repeats that fold into a β-propeller structure. Originally discovered as an intracellular receptor for activated protein kinase C (PKC), RACK1 facilitates binding and localization of PKC isoforms, linking kinase signaling to specific subcellular locations and functional outputs. RACK1 is a bona fide core component of the eukaryotic 40S ribosomal subunit, integrating multiple cellular signaling events to regulate translation and ribosome biogenesis. Through its scaffold function, RACK1 coordinates diverse signaling pathways—including Src, STAT1, Janus kinase (Jak), and others—that control processes such as cell growth, migration, immune response, and stress adaptation. Altered RACK1 expression or function has been implicated in cancer, inflammatory disorders, neurodegeneration, and cardiovascular diseases, making it a central hub of cellular regulation and a potential therapeutic target—although its lack of direct catalytic activity and broad cellular role make targeted pharmacological intervention challenging.

Other names

Guanine nucleotide-binding protein subunit beta-2-like 1GNB2L1Small ribosomal subunit protein RACK1Cell proliferation-inducing gene 21 proteinGuanine nucleotide-binding protein subunit beta-like protein 12.3HLC-7Human lung cancer oncogene 7 proteinReceptor of activated protein C kinase 1

Scaffold for protein-protein interactions in signaling pathways (especially PKC recruitment/activation) Modulation of ribosome function and translation in response to signaling events Regulation of Jak-STAT, Src kinase, and other pathways