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
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the RACK1
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Function
RACK1 was originally isolated and identified as an intracellular protein receptor for
protein kinase C
In cell biology, protein kinase C, commonly abbreviated to PKC (EC 2.7.11.13), is a family of protein kinase enzymes that are involved in controlling the function of other proteins through the phosphorylation of hydroxyl groups of serine and t ...
, noting the significant homology to the beta subunit of
heterotrimeric G protein
Heterotrimeric G protein, also sometimes referred to as the ''"large" G proteins'' (as opposed to the subclass of smaller, monomeric small GTPases) are membrane-associated G proteins that form a Heteromer, heterotrimeric complex. The biggest no ...
s.
Later studies established RACK1, and its yeast homolog Asc1, as a core
ribosomal protein
A ribosomal protein (r-protein or rProtein) is any of the proteins that, in conjunction with rRNA, make up the ribosomal subunits involved in the cellular process of translation. ''E. coli'', other bacteria and Archaea have a 30S small subunit ...
of the
eukaryotic small (40S) ribosomal subunit.
Much of the function of Asc1/RACK1 appears to result from its position on the 'head' of the 40S ribosomal subunit.
Asc1/RACK1 participates in several aspects of
eukaryotic translation
Eukaryotic translation is the biological process by which messenger RNA is Translation (biology), translated into proteins in eukaryotes. It consists of four phases: initiation, elongation, termination, and recapping.
Initiation
Translation init ...
and
ribosome quality control, including
IRES-mediated translation,
,
non-functional
18S ribosomal RNA
18S ribosomal RNA (abbreviated 18S rRNA) is a part of the ribosomal RNA in eukaryotes. It is a component of the Eukaryotic small ribosomal subunit (40S) and the cytosolic homologue of both the 12S ribosomal RNA, 12S rRNA in mitochondria and the 1 ...
decay,
and
frameshifting.
Interactions
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
18S ribosomal RNA (abbreviated 18S rRNA) is a part of the ribosomal RNA in eukaryotes. It is a component of the Eukaryotic small ribosomal subunit (40S) and the cytosolic homologue of both the 12S rRNA in mitochondria and the 16S rRNA in plas ...
and other
ribosomal proteins, including
uS3,
uS9, and
eS17. Additionally, RACK1 has been shown to
interact with:
*
AGTRAP
*
Androgen receptor
The androgen receptor (AR), also known as NR3C4 (nuclear receptor subfamily 3, group C, member 4), is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone, in th ...
,
*
CD18,
*
CD29Cyclin A1
Cyclin-A1 is a protein that in humans is encoded by the ''CCNA1'' gene.
Function
The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance th ...
Janus kinase 1
Janus kinase 1 (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 f ...
[
* OTUB1,]P73
p73 is a protein related to the p53 tumor protein. Because of its structural resemblance to p53, it has also been considered a tumor suppressor. It is involved in cell cycle regulation, and induction of apoptosis. Like p53, p73 is characterized ...
,PDE4D
cAMP-specific 3',5'-cyclic phosphodiesterase 4D is an enzyme that in humans is encoded by the ''PDE4D'' gene.
Function
The PDE4D gene is complex and has at least 9 different isoforms that encode functional proteins. These proteins degrade the ...
,PRKCB1
Protein kinase C beta type is an enzyme that in humans is encoded by the ''PRKCB'' gene.
Protein kinase C (PKC) is a family of serine- and threonine-specific protein kinases that can be activated by calcium and second messenger diacylglycerol. PK ...
,Tyrosine kinase 2
Non-receptor tyrosine-protein kinase TYK2 is an enzyme that in humans is encoded by the ''TYK2'' gene.
TYK2 was the first member of the JAK family that was described (the other members are JAK1, JAK2, and JAK3). It has been implicated in IF ...
.[
]
See also
* Eukaryotic small ribosomal subunit (40S)
The eukaryotic small ribosomal subunit (40S) is the smaller subunit of the 80S, eukaryotic 80S ribosomes, with the other major component being the eukaryotic large ribosomal subunit (60S), large ribosomal subunit (60S). The "40S" and "60S" names o ...
* Protein kinase C
In cell biology, protein kinase C, commonly abbreviated to PKC (EC 2.7.11.13), is a family of protein kinase enzymes that are involved in controlling the function of other proteins through the phosphorylation of hydroxyl groups of serine and t ...
* Heterotrimeric G protein
Heterotrimeric G protein, also sometimes referred to as the ''"large" G proteins'' (as opposed to the subclass of smaller, monomeric small GTPases) are membrane-associated G proteins that form a Heteromer, heterotrimeric complex. The biggest no ...
References
Further reading
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{{Ribosome subunits
Ribosomal proteins