Receptor for activated C kinase 1 (RACK1), also known as guanine nucleotide-binding protein subunit beta-2-like 1 (GNB2L1), is a 35
kDa
The dalton or unified atomic mass unit (symbols: Da or u) is a non-SI unit of mass widely used in physics and chemistry. It is defined as of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at ...
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
that in humans is encoded by the RACK1
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
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 an ...
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 translated into proteins in eukaryotes. It consists of four phases: gene translation, elongation, termination, and recapping.
Initiation
Translation initiation is the pr ...
and
ribosome quality control, including
IRES-mediated translation,
non-stop decay
Non-stop decay (NSD) is a cellular mechanism of mRNA surveillance to detect mRNA molecules lacking a stop codon and prevent these mRNAs from translation. The non-stop decay pathway releases ribosomes that have reached the far 3' end of an mRNA and ...
,
non-functional
18S ribosomal RNA
18S ribosomal RNA (abbreviated 18S rRNA) is a part of the ribosomal RNA. The S in 18S represents Svedberg units. 18S rRNA is an SSU rRNA, a component of the eukaryotic ribosomal small subunit (40S). 18S rRNA is the structural RNA for the small c ...
decay,
and
frameshifting
A frameshift mutation (also called a framing error or a reading frame shift) is a genetic mutation caused by indels ( insertions or deletions) of a number of nucleotides in a DNA sequence that is not divisible by three. Due to the triplet nature ...
.
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 may refer to:
*18S ribosomal RNA
*18S rRNA (adenine1779-N6/adenine1780-N6)-dimethyltransferase
*18SEH
The Family II is a straight-4 piston engine that was originally developed by Opel in the 1970s, debuting in 1979. Available in a wide ran ...
and other
ribosomal proteins
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 an ...
, including
uS3,
uS9, and
eS17. Additionally, RACK1 has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with:
*
AGTRAP
Type-1 angiotensin II receptor-associated protein is a protein that in humans is encoded by the ''AGTRAP'' gene.
This gene encodes a transmembrane protein localized to the plasma membrane and perinuclear vesicular structures. The gene product int ...
*
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
In molecular biology, CD18 (Integrin beta chain-2) is an integrin beta chain protein that is encoded by the ''ITGB2'' gene in humans. Upon binding with one of a number of alpha chains, CD18 is capable of forming multiple heterodimers, which play ...
,
*
CD29
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 r ...
* Cyclin 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 thro ...
* EIF6
Eukaryotic translation initiation factor 6 (EIF6), also known as Integrin beta 4 binding protein (ITGB4BP), is a human gene.
Hemidesmosomes are structures which link the basal lamina to the intermediate filament cytoskeleton. An important functio ...
,
* FYN
Funen ( da, Fyn, ), with an area of , is the third-largest island of Denmark, after Zealand and Vendsyssel-Thy. It is the 165th-largest island in the world. It is located in the central part of the country and has a population of 469,947 as of ...
,
* IFNAR2
Interferon-alpha/beta receptor beta chain is a protein that in humans is encoded by the ''IFNAR2'' gene.
Function
The protein encoded by this gene is a type I membrane protein that forms one of the two chains of a receptor for interferons alp ...
,
* 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 family (e.g. IL-2R, I ...
[
* ]OTUB1
Ubiquitin thioesterase OTUB1 also known as otubain-1 is an enzyme that in humans is encoded by the ''OTUB1'' gene. Alternative splicing results in multiple transcript variants.
Function
Otubain-1 is a member of the OTU (ovarian tumor) superfami ...
,
* 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 s ...
,
* 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 ...
,
* PRKCE
Protein kinase C epsilon type (PKCε) is an enzyme that in humans is encoded by the ''PRKCE'' gene. PKCε is an isoform of the large PKC family of protein kinases that play many roles in different tissues. In cardiac muscle cells, PKCε regulate ...
,
* PTPRM
Receptor-type tyrosine-protein phosphatase mu is an enzyme that in humans is encoded by the ''PTPRM'' gene.
Function
The protein encoded by this gene is a member of the protein tyrosine phosphatase (PTP) family. Protein tyrosine phosphatases a ...
,
* RAS p21 protein activator 1
RAS p21 protein activator 1 or RasGAP (Ras GTPase activating protein), also known as RASA1, is a 120-kDa cytosolic human protein that provides two principal activities:
* Inactivation of Ras from its active GTP-bound form to its inactive GDP-boun ...
,
* ST7,
* STAT1
Signal transducer and activator of transcription 1 (STAT1) is a transcription factor which in humans is encoded by the ''STAT1'' gene. It is a member of the STAT protein family.
Function
All STAT molecules are phosphorylated by receptor associa ...
,
* Src, and
* 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 IFN-α, ...
.[
]
See also
* Eukaryotic small ribosomal subunit (40S)
The eukaryotic small ribosomal subunit (40S) is the smaller subunit of the eukaryotic 80S ribosomes, with the other major component being the large ribosomal subunit (60S). The "40S" and "60S" names originate from the convention that ribosomal pa ...
* 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