Small ubiquitin-related modifier 1 is a
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 ''SUMO1''
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
This gene encodes a protein that is a member of the
SUMO
is a form of competitive full-contact wrestling where a ''rikishi'' (wrestler) attempts to force his opponent out of a circular ring (''dohyō'') or into touching the ground with any body part other than the soles of his feet (usually by thr ...
(small ubiquitin-like modifier) protein family. It is a
ubiquitin-like protein
Ubiquitin-like proteins (UBLs) are a family of small proteins involved in post-translational modification of other proteins in a cell, usually with a regulatory function. The UBL protein family derives its name from the first member of the class ...
and functions in a manner similar to
ubiquitin
Ubiquitin is a small (8.6 kDa) regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ''ubiquitously''. It was discovered in 1975 by Gideon Goldstein and further characterized throughout the late 1970s and 1980s. Fo ...
in that it is bound to target proteins as part of a
post-translational modification
Post-translational modification (PTM) is the covalent and generally enzymatic modification of proteins following protein biosynthesis. This process occurs in the endoplasmic reticulum and the golgi apparatus. Proteins are synthesized by ribosome ...
system. However, unlike ubiquitin, which is primarily associated with targeting proteins for
proteasomal degradation
Proteasomes are protein complexes which degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds. Enzymes that help such reactions are called proteases.
Proteasomes are part of a major mechanism by w ...
, SUMO1 is involved in a variety of cellular processes, such as nuclear transport, transcriptional regulation, apoptosis, and protein stability. It is not active until the last four amino acids of the
carboxy-terminus
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is ...
have been cleaved off. Several
pseudogene
Pseudogenes are nonfunctional segments of DNA that resemble functional genes. Most arise as superfluous copies of functional genes, either directly by DNA duplication or indirectly by Reverse transcriptase, reverse transcription of an mRNA trans ...
s have been reported for this gene. Alternate transcriptional
splice variant
Alternative splicing, or alternative RNA splicing, or differential splicing, is an alternative splicing process during gene expression that allows a single gene to code for multiple proteins. In this process, particular exons of a gene may be in ...
s encoding different
isoform
A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene or gene family and are the result of genetic differences. While many perform the same or similar biological roles, some isof ...
s have been characterized.
Most
cleft
A cleft is an opening, fissure, or V-shaped indentation.
Cleft may refer to:
Linguistics
* A cleft sentence, a type of grammatical construction
Anatomy
* Cleft lip and palate, a congenital deformity
* A cleft chin, a dimple on the chin
* The ...
genes have a
sumoylation
In molecular biology, SUMO (Small Ubiquitin-like Modifier) proteins are a family of small proteins that are covalently attached to and detached from other proteins in cells to modify their function. This process is called SUMOylation (sometimes w ...
component. Analysis of chromosomal anomalies in patients has led to the identification and confirmation of SUMO1 as a
cleft lip and palate
A cleft lip contains an opening in the upper lip that may extend into the nose. The opening may be on one side, both sides, or in the middle. A cleft palate occurs when the palate (the roof of the mouth) contains an opening into the nose. The ...
locus.
Interactions
Small ubiquitin-related modifier 1 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:
*
C22orf25
Transport and golgi organization 2 homolog (TANGO2) also known as chromosome 22 open reading frame 25 (C22orf25) is a protein that in humans is encoded by the TANGO2 gene.
The function of C22orf25 is not currently known. It is characterized by ...
,
*
DAXX
Death-associated protein 6 also known as Daxx is a protein that in humans is encoded by the ''DAXX'' gene.
Function
Daxx, a Death domain-associated protein, was first discovered through its cytoplasmic interaction with the classical death r ...
,
*
DNMT3B
DNA (cytosine-5)-methyltransferase 3 beta, is an enzyme that in humans in encoded by the DNMT3B gene. Mutation in this gene are associated with immunodeficiency, centromere instability and facial anomalies syndrome.
Function
CpG methylation i ...
,
*
P53
p53, also known as Tumor protein P53, cellular tumor antigen p53 (UniProt name), or transformation-related protein 53 (TRP53) is a regulatory protein that is often mutated in human cancers. The p53 proteins (originally thought to be, and often s ...
,
[
* ]PIAS1
E3 SUMO-protein ligase PIAS1 is an enzyme that in humans is encoded by the ''PIAS1'' gene.
Function
This gene encodes a member of the mammalian PIAS rotein inhibitor of activated STAT-1 (signal transducer and activator of transcription-1)famil ...
,
* PML,
* SAE2,
* SP1,
* TDG,
* TNFRSF1A
Tumor necrosis factor receptor 1 (TNFR1), also known as tumor necrosis factor receptor superfamily member 1A (TNFRSF1A) and CD120a, is a ubiquitous membrane receptor that binds tumor necrosis factor-alpha (TNFα).
Function
The protein encoded b ...
,
* TNFRSF6
The Fas receptor, also known as Fas, FasR, apoptosis antigen 1 (APO-1 or APT), cluster of differentiation 95 (CD95) or tumor necrosis factor receptor superfamily member 6 (TNFRSF6), is a protein that in humans is encoded by the ''FAS'' gene. Fas ...
,[
* ]TOP2A
DNA topoisomerase IIα is a human enzyme encoded by the ''TOP2A'' gene.
Topoisomerase IIα relives topological DNA stress during transcription, condenses chromosomes, and separates chromatids. It catalyzes the transient breaking and rejoining of ...
,[
* ]TOP2B
DNA topoisomerase 2-beta is an enzyme that in humans is encoded by the ''TOP2B'' gene.
Function
This gene encodes a DNA topoisomerase, an enzyme that controls and alters the topologic states of DNA during transcription. This nuclear enzyme is ...
, and
* UBE2I
SUMO-conjugating enzyme UBC9 is an enzyme that in humans is encoded by the ''UBE2I'' gene. It is also sometimes referred to as "ubiquitin conjugating enzyme E2I" or "ubiquitin carrier protein 9", even though these names do not accurately describe ...
,
Role in the heart
Heart failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...
is a process by which the heart’s pumping ability is significantly weakened, so that the body is unable to get adequate circulation. A weakened heart results in symptoms of fatigue, decreased exercise tolerance and shortness of breath. Patients with heart failure have a significantly increased risk of death compared to people with normal heart function. Heart failure is a major public health concern, as its incidence is on the rise worldwide, and is a leading cause of death in developed nations
SUMO 1 is a key component in cardiac function, since it helps regulate calcium homeostasis in the mitochondria
A mitochondrion (; ) is an organelle found in the Cell (biology), cells of most Eukaryotes, such as animals, plants and Fungus, fungi. Mitochondria have a double lipid bilayer, membrane structure and use aerobic respiration to generate adenosi ...
of heart cells. SUMO 1 is associated with another essential cardiac protein called sarco/endoplasmic reticulum Ca2+ ATPase, or SERCA2A. SERCA SERCA, or sarco/endoplasmic reticulum Ca2+-ATPase, or SR Ca2+-ATPase, is a calcium ATPase-type P-ATPase. Its major function is to transport calcium from the cytosol into the sarcoplasmic reticulum.
Function
SERCA is a P-type ATPase. It resides i ...
is a transmembrane protein located in the sarcoplasmic reticulum
The sarcoplasmic reticulum (SR) is a membrane-bound structure found within muscle cells that is similar to the smooth endoplasmic reticulum in other Cell (biology), cells. The main function of the SR is to store calcium ions (Ca2+). Calcium in bio ...
of cardiac cells. Its main function is to regulate the discharge and uptake of intracellular calcium between the cytosol and the lumen of the sarcoplasmic reticulum. Calcium is an essential factor for the development of cardiac myocyte contraction and relaxation. Thus, the management of intracellular calcium homeostasis by SERCA2A is critical for overall cardiac performance. Normally, SUMO 1 activates and stabilizes SERCA2A by binding at lysine resides 480 and 585. The interaction between SUMO 1 and SERCA2A is crucial for regulating calcium levels inside cardiac myocytes. Reduction in SUMO 1 protein reduces SERCA2A, and thus efficient calcium handling in patients with failing hearts.
As a drug target
SUMO 1 may be an important therapeutic target to help improve cardiac performance in patients with heart failure. In a mouse model, the introduction of SUMO 1 through gene therapy was associated with improved activity of SERCA2A, which resulted in improved cardiac function through an augmentation of cardiac contractility. Furthermore, overexpression of SUMO 1 resulted in accelerated calcium uptake, providing further evidence regarding its importance in maintaining adequate calcium levels in heart cells.
See also
* SENP6
Sentrin-specific protease 6 is an enzyme that in humans is encoded by the ''SENP6'' gene.
Function
Ubiquitin-like molecules (UBLs), such as SUMO1, are structurally related to ubiquitin and can be ligated to target proteins in a similar manner ...
References
Further reading
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
External links
*
*
{{PDB Gallery, geneid=7341