Ubiquitin-conjugating enzyme E2 L3 (UBE2L3), also called UBCH7, 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 ''UBE2L3''

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 ...

. As an E2 enzyme, UBE2L3 participates in

ubiquitination 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 ...

to target proteins for degradation. The role of UBE2L3 in the ubiquitination of the NF-κB precursor implicated it in various major autoimmune diseases, including

rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involv ...

(RA),

celiac disease Coeliac disease (British English) or celiac disease (American English) is a long-term autoimmune disorder, primarily affecting the small intestine, where individuals develop intolerance to gluten, present in foods such as wheat, rye and barl ...

Crohn's disease Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, abdominal distension ...

(CD), and

systemic lupus erythematosus Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Comm ...

Structure

Gene

The ''UBE2L3'' gene is located at

chromosome 22 Chromosome 22 is one of the 23 pairs of chromosomes in human cell (biology), cells. Humans normally have two copies of chromosome 22 in each cell. Chromosome 22 is the second smallest human chromosome, spanning about 49 million DNA base pairs and ...

q11.21, consisting of 6

exons An exon is any part of a gene that will form a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term ''exon'' refers to both the DNA sequence within a gene and to the corresponding sequence ...

. Two alternatively spliced transcript variants encoding distinct isoforms have been found for this gene.

Protein

There are 38 E2 enzymes in humans. They all contain a conserved catalytic core

domain Domain may refer to: Mathematics *Domain of a function, the set of input values for which the (total) function is defined **Domain of definition of a partial function **Natural domain of a partial function **Domain of holomorphy of a function * Do ...

that interacts with E1 and E3 and many E2s possess additional N- and/or

C-terminal 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 ...

protein sequences. In contrast to other E2s, residues necessary for

lysine Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins. It contains an α-amino group (which is in the protonated form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −C ...

reactivity are absent: the D87 and D117 residues (in UBCH5C numbering) are replaced by

Pro Pro is an abbreviation meaning "professional". Pro, PRO or variants thereof may also refer to: People * Miguel Pro (1891–1927), Mexican priest * Pro Hart (1928–2006), Australian painter * Mlungisi Mdluli (born 1980), South African retired f ...

and

His His or HIS may refer to: Computing * Hightech Information System, a Hong Kong graphics card company * Honeywell Information Systems * Hybrid intelligent system * Microsoft Host Integration Server Education * Hangzhou International School, in ...

residues.

Function

The modification of proteins with

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 ...

is an important cellular mechanism for targeting abnormal or short-lived proteins for

degradation Degradation may refer to: Science * Degradation (geology), lowering of a fluvial surface by erosion * Degradation (telecommunications), of an electronic signal * Biodegradation of organic substances by living organisms * Environmental degradatio ...

. Ubiquitination involves at least three classes of enzymes: ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s) and ubiquitin-protein ligases (E3s). E2s play a key role in the whole ubiquitin (Ub) transfer pathway and are responsible for Ub

cellular signaling In biology, cell signaling (cell signalling in British English) or cell communication is the ability of a cell to receive, process, and transmit signals with its environment and with itself. Cell signaling is a fundamental property of all cellula ...

. Unlike many E2s that transfer Ub with RINGs, UBE2L3 has E3-independent reactivity with lysine. This enzyme is demonstrated to participate in the ubiquitination of

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 ...

c-Fos Protein c-Fos is a proto-oncogene that is the human homolog of the retroviral oncogene v-fos. It is encoded in humans by the ''FOS'' gene. It was first discovered in rat fibroblasts as the transforming gene of the FBJ MSV (Finkel–Biskis–Jinkin ...

, and the

NF-κB Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a protein complex that controls transcription of DNA, cytokine production and cell survival. NF-κB is found in almost all animal cell types and is involved in cellular ...

precursor p105 in vitro. UBE2L3 is primarily known for its role in the

cell cycle The cell cycle, or cell-division cycle, is the series of events that take place in a cell that cause it to divide into two daughter cells. These events include the duplication of its DNA (DNA replication) and some of its organelles, and subs ...

. Specifically, UBE2L3 manages cell cycle regulatory protein levels via the ubiquitin proteolytic pathway (UPP) during the G1/S transition and during the actual

S phase S phase (Synthesis Phase) is the phase of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Since accurate duplication of the genome is critical to successful cell division, the processes that occur during ...

Clinical significance

Through

genome-wide association studies In genomics, a genome-wide association study (GWA study, or GWAS), also known as whole genome association study (WGA study, or WGAS), is an observational study of a genome-wide set of genetic variants in different individuals to see if any varian ...

(GWAS), UBE2L3 has been associated with several autoimmune diseases, including RA,

, CD, and

SLE Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Commo ...

via the ubiquitination of the NK-κB precursor. This association was observed in European, Asian, and African-American populations. UBE2L3 has been linked to natural killer cell cytotoxic function, and high UBE2L3 levels had contributed to clearing chronic HBV infection. UBE2L3 controls the protein stability of

53BP1 Tumor suppressor p53-binding protein 1 also known as p53-binding protein 1 or 53BP1 is a protein that in humans is encoded by the ''TP53BP1'' gene. Clinical significance 53BP1 is underexpressed in most cases of triple-negative breast cancer. D ...

and determines the DNA

double-strand break DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA dam ...

repair choice. Loss of UBE2L3 stabilizes 53BP1 and force cells to choose

NHEJ Non-homologous end joining (NHEJ) is a pathway that repairs double-strand breaks in DNA. NHEJ is referred to as "non-homologous" because the break ends are directly ligated without the need for a homologous template, in contrast to homology direc ...

to repair DNA double-strand break. Repair by NHEJ leads to radial chromosomes and cell death. UBE2L3 depletion may become a novel strategy in enhancing the effect of anticancer therapies. The haplotype of ''UBE2L3'' gene is also reported associated with

Hashimoto's thyroiditis Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis and Hashimoto's disease, is an autoimmune disease in which the thyroid gland is gradually destroyed. Early on, symptoms may not be noticed. Over time, the thyroid may enlarg ...

in a Chinese Han population.(27094594)

Interactions

UBE2L3 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: *

ARIH1 Protein ariadne-1 homolog is a protein that in humans is encoded by the ''ARIH1'' gene. Interactions ARIH1 has been shown to interact with: * EIF4E2, and * UBE2L3 Ubiquitin-conjugating enzyme E2 L3 (UBE2L3), also called UBCH7, is a protein that ...

, * ARIH2, * CBL, *

CHEK1 Checkpoint kinase 1, commonly referred to as Chk1, is a serine/threonine-specific protein kinase that, in humans, is encoded by the ''CHEK1'' gene. Chk1 coordinates the DNA damage response (DDR) and cell cycle checkpoint response. Activation of Chk ...

, *

NEDD4 E3 ubiquitin-protein ligase NEDD4, also known as neural precursor cell expressed developmentally down-regulated protein 4 (whence "NEDD4") is an enzyme that is, in humans, encoded by the ''NEDD4'' gene. NEDD4 is an E3 ubiquitin ligase enzyme, that ...

, *

PARK2 Parkin is a 465-amino acid residue E3 ubiquitin ligase, a protein that in humans and mice is encoded by the ''PARK2'' gene. Parkin plays a critical role in ubiquitination – the process whereby molecules are covalently labelled with ubiquitin (Ub ...

, *

SMURF2 E3 ubiquitin-protein ligase SMURF2 is an enzyme that in humans is encoded by the ''SMURF2'' gene which is located at chromosome 17q23.3-q24.1. Interactions SMURF2 has been shown to interact with: * Mothers against decapentaplegic homolog 1, * ...

, *

TNFAIP3 Tumor necrosis factor, alpha-induced protein 3 or A20 is a protein that in humans is encoded by the ''TNFAIP3'' gene. This gene was identified as a gene whose expression is rapidly induced by the tumor necrosis factor (TNF). The protein encoded ...

, *

TNFSF4 OX40L is the ligand for OX40 (also known as CD134 or TNFRSF4) and is stably expressed on many antigen-presenting cells such as DC2s (a subtype of dendritic cells), macrophages, and activated B lymphocytes. The OX40 molecule, conversely, is pre ...

, *

TNIP1 TNFAIP3-interacting protein 1, also known as ABIN-1, is a protein that in humans is encoded by the ''TNIP1'' gene. Association with autoimmune diseases Genetic variations within the region of the ''TNIP1'' gene have been shown to have associ ...

, *

TRAF6 TRAF6 is a TRAF human protein. Function The protein encoded by this gene is a member of the TNF receptor associated factor (TRAF) protein family. TRAF proteins are associated with, and mediate signal transduction from members of the TNF recep ...

, *

UBE3A Ubiquitin-protein ligase E3A (UBE3A) also known as E6AP ubiquitin-protein ligase (E6AP) is an enzyme that in humans is encoded by the ''UBE3A'' gene. This enzyme is involved in targeting proteins for degradation within cells. Protein degradation ...

, *

, and * UBOX5.

Structure

Gene

Protein

Function

Clinical significance

Interactions

References

External links

Further reading