Probable ATP-dependent RNA helicase DDX20, also known as DEAD-box helicase 20 and gem-associated protein 3 (GEMIN3), is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

that in humans is encoded by the ''DDX20''

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

DEAD box Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...

proteins, characterized by the conserved motif Asp-Glu-Ala-Asp (DEAD), are putative

RNA helicase Helicases are a class of enzymes thought to be vital to all organisms. Their main function is to unpack an organism's genetic material. Helicases are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separating ...

s. They are implicated in a number of cellular processes involving alteration of RNA secondary structure such as translation initiation, nuclear and mitochondrial splicing, and

ribosome Ribosomes ( ) are macromolecular machines, found within all cells, that perform biological protein synthesis (mRNA translation). Ribosomes link amino acids together in the order specified by the codons of messenger RNA (mRNA) molecules to ...

and

spliceosome A spliceosome is a large ribonucleoprotein (RNP) complex found primarily within the nucleus of eukaryotic cells. The spliceosome is assembled from small nuclear RNAs (snRNA) and numerous proteins. Small nuclear RNA (snRNA) molecules bind to specifi ...

assembly. Based on their distribution patterns, some members of this family are believed to be involved in

embryogenesis An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm ...

spermatogenesis Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubule ...

, and cellular growth and division. This gene encodes a DEAD box protein, which has an

ATPase ATPases (, Adenosine 5'-TriPhosphatase, adenylpyrophosphatase, ATP monophosphatase, triphosphatase, SV40 T-antigen, ATP hydrolase, complex V (mitochondrial electron transport), (Ca2+ + Mg2+)-ATPase, HCO3−-ATPase, adenosine triphosphatase) are ...

activity and is a component of the

survival of motor neuron Survival of motor neuron or survival motor neuron (SMN) is a protein that in humans is encoded by the ''SMN1'' and ''SMN2'' genes. SMN is found in the cytoplasm of all animal cells and also in the nuclear gems. It functions in transcriptional reg ...

(SMN) complex. SMN is the spinal muscular atrophy gene product, and may play a catalytic role in the function of the SMN complex on RNPs.

Clinical significance

Previous research has revealed that DDX20 may act as a tumor suppressor in

hepatocellular carcinoma Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults and is currently the most common cause of death in people with cirrhosis. HCC is the third leading cause of cancer-related deaths worldwide. It occurs in t ...

and as a

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

promoter in

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...

. DDX20 deficiency enhances

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 ...

activity by impairing the NF-κB-suppressive action of

microRNA MicroRNA (miRNA) are small, single-stranded, non-coding RNA molecules containing 21 to 23 nucleotides. Found in plants, animals and some viruses, miRNAs are involved in RNA silencing and post-transcriptional regulation of gene expression. miRN ...

s, and suggest that dysregulation of the microRNA machinery components may also be involved in pathogenesis in various human diseases. Such as miRNA-140 which acts as a liver tumor suppressor, and due to a deficiency of DDX20, miRNA-140 function gets impair, this subsequent functional impairment of miRNAs could lead to hepatocarcinogenesis. Similarly, DDX20 may promote the progression of

Prostate cancer Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that sur ...

(PCa) through the NF-κB pathway. In a clinical based study it has been observed that positive DP103/NF-κB feedback loop promotes constitutive NF-κB activation in invasive breast cancers and activation of this pathway is linked to cancer progression and the acquisition of

chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...

resistance. It makes DP103 has potential as a therapeutic target for breast cancer treatment.

Interactions

DDX20 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: *

EIF2C2 Protein argonaute-2 is a protein that in humans is encoded by the ''EIF2C2'' gene. This gene encodes a member of the Argonaute family of proteins which play a role in RNA interference. The encoded protein is highly basic, and contains a PAZ dom ...

, *

GEMIN4 Gem-associated protein 4 is a protein that in humans is encoded by the ''GEMIN4'' gene. Function The product of this gene is part of the SMN protein complex localized to the cytoplasm, nucleoli, and to discrete nuclear bodies called Gemini b ...

, *

GEMIN5 Gem-associated protein 5 is a protein that in humans is encoded by the ''GEMIN5'' gene. Function Gem-associated protein 5 is part of the survival of motor neuron protein, SMN a large protein complex localized to both the cytoplasm and the cell ...

, *

LSM2 U6 snRNA-associated Sm-like protein LSm2 is a protein that in humans is encoded by the ''LSM2'' gene. Function Sm-like proteins were identified in a variety of organisms based on sequence homology with the Sm protein family (see SNRPD2; MIM 60 ...

, *

SMN1 Survival of motor neuron 1 (''SMN1''), also known as component of gems 1 or ''GEMIN1'', is a gene that encodes the SMN protein in humans. Gene ''SMN1'' is the telomeric copy of the gene encoding the SMN protein; the centromeric copy is terme ...

, *

SNRPB Small nuclear ribonucleoprotein-associated proteins B and B' is a protein that in humans is encoded by the ''SNRPB'' gene. Function The protein encoded by this gene is one of several nuclear proteins that are found in common among U1, U2, U4/U ...

, *

SNRPD3 Small nuclear ribonucleoprotein Sm D3 is a protein that in humans is encoded by the ''SNRPD3'' gene. Function The protein encoded by this gene belongs to the small nuclear ribonucleoprotein core protein family. It is required for pre-mRNA splic ...

and *

SNRPG Small nuclear ribonucleoprotein G is a protein that in humans is encoded by the ''SNRPG'' gene. Interactions SNRPG has been shown to interact with DDX20 and TACC1 Transforming acidic coiled-coil-containing protein 1 is a protein that in human ...

, * SNRPD1, * SNRPD2, * SNRPE, *

SNRPF Small nuclear ribonucleoprotein F is a protein that in humans is encoded by the ''SNRPF'' gene. Interactions Small nuclear ribonucleoprotein polypeptide F has been shown to interact with DDX20, Small nuclear ribonucleoprotein D2 and Small nucl ...

, and * SIP1.

Function

Clinical significance

Interactions

References

Further reading