Receptor for activated C kinase 1 (RACK1), also known as guanine nucleotide-binding protein subunit beta-2-like 1 (GNB2L1), is a 35 kDa protein that in humans is encoded by the RACK1 gene. [4] [5]
RACK1 was originally isolated and identified as an intracellular protein receptor for protein kinase C, noting the significant homology to the beta subunit of heterotrimeric G proteins. [4] Later studies established RACK1, and its yeast homolog Asc1, as a core ribosomal protein of the eukaryotic small (40S) ribosomal subunit. [6] [7] [8] Much of the function of Asc1/RACK1 appears to result from its position on the 'head' of the 40S ribosomal subunit. [9] Asc1/RACK1 participates in several aspects of eukaryotic translation and ribosome quality control, including IRES-mediated translation, [10] non-stop decay, [11] non-functional 18S ribosomal RNA decay, [12] and frameshifting. [13]
RACK1 is positioned at the solvent-exposed surface of the 40S ribosomal subunit, where it is held in place through contacts with both the 18S rRNA and other ribosomal proteins, including uS3, uS9, and eS17. Additionally, RACK1 has been shown to interact with:
Growth factor receptor-bound protein 2 also known as Grb2 is an adaptor protein involved in signal transduction/cell communication. In humans, the GRB2 protein is encoded by the GRB2 gene.
Transforming growth factor, beta receptor II (70/80kDa) is a TGF beta receptor. TGFBR2 is its human gene.
Integrin beta-1 (ITGB1), also known as CD29, is a cell surface receptor that in humans is encoded by the ITGB1 gene. This integrin associates with integrin alpha 1 and integrin alpha 2 to form integrin complexes which function as collagen receptors. It also forms dimers with integrin alpha 3 to form integrin receptors for netrin 1 and reelin. These and other integrin beta 1 complexes have been historically known as very late activation (VLA) antigens.
JAK1 is a human tyrosine kinase protein essential for signaling for certain type I and type II cytokines. It interacts with the common gamma chain (γc) of type I cytokine receptors, to elicit signals from the IL-2 receptor family, the IL-4 receptor family, the gp130 receptor family. It is also important for transducing a signal by type I (IFN-α/β) and type II (IFN-γ) interferons, and members of the IL-10 family via type II cytokine receptors. Jak1 plays a critical role in initiating responses to multiple major cytokine receptor families. Loss of Jak1 is lethal in neonatal mice, possibly due to difficulties suckling. Expression of JAK1 in cancer cells enables individual cells to contract, potentially allowing them to escape their tumor and metastasize to other parts of the body.
The nuclear receptor coactivator 1 (NCOA1) is a transcriptional coregulatory protein that contains several nuclear receptor interacting domains and an intrinsic histone acetyltransferase activity. NCOA1 is recruited to DNA promotion sites by ligand-activated nuclear receptors. NCOA1, in turn, acylates histones, which makes downstream DNA more accessible to transcription. Hence, NCOA1 assists nuclear receptors in the upregulation of DNA expression.
Serine/threonine-protein kinase PAK 1 is an enzyme that in humans is encoded by the PAK1 gene.
Caveolin-1 is a protein that in humans is encoded by the CAV1 gene.
Protein kinase C beta type is an enzyme that in humans is encoded by the PRKCB gene.
Phosphatidylinositol 3-kinase regulatory subunit beta is an enzyme that in humans is encoded by the PIK3R2 gene.
Interleukin enhancer-binding factor 3 is a protein that in humans is encoded by the ILF3 gene.
60S ribosomal protein L5 is a protein that in humans is encoded by the RPL5 gene.
Elongation factor 1-delta is a protein that in humans is encoded by the EEF1D gene.
Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B alpha isoform is an enzyme regulator that in humans is encoded by the PPP2R2A gene.
Ribosomal protein S6 kinase alpha-1 is an enzyme that in humans is encoded by the RPS6KA1 gene.
Eukaryotic translation initiation factor 2 subunit 1 (eIF2α) is a protein that in humans is encoded by the EIF2S1 gene.
Eukaryotic translation initiation factor 6 (EIF6), also known as Integrin beta 4 binding protein (ITGB4BP), is a human gene.
5'-AMP-activated protein kinase subunit gamma-1 is an enzyme that in humans is encoded by the PRKAG1 gene.
60S ribosomal protein L7 is a protein that in humans is encoded by the RPL7 gene.
Eukaryotic translation initiation factor 2A (eIF2A) is a protein that in humans is encoded by the EIF2A gene. The eIF2A protein is not to be confused with eIF2α, a subunit of the heterotrimeric eIF2 complex. Instead, eIF2A functions by a separate mechanism in eukaryotic translation.
cGMP-dependent protein kinase 1, alpha isozyme is an enzyme that in humans is encoded by the PRKG1 gene.