M-phase inducer phosphatase 1 also known as dual specificity phosphatase Cdc25A is a

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 cell division cycle 25 homolog A (CDC25A)

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

CDC25A is a member of the

CDC25 Cdc25 is a dual-specificity phosphatase first isolated from the yeast ''Schizosaccharomyces pombe'' as a cell cycle defective mutant. As with other cell cycle proteins or genes such as Cdc2 and Cdc4, the "cdc" in its name refers to "cell divis ...

family of dual-specificity phosphatases. Dual-specificity protein

phosphatase In biochemistry, a phosphatase is an enzyme that uses water to cleave a phosphoric acid Ester, monoester into a phosphate ion and an Alcohol (chemistry), alcohol. Because a phosphatase enzyme catalysis, catalyzes the hydrolysis of its Substrate ...

s remove

phosphate group Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosp ...

s from phosphorylated

tyrosine -Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a conditionally essential amino acid with a polar side group. The word "tyrosine" is ...

and

serine Serine (symbol Ser or S) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α- amino group (which is in the protonated − form under biological conditions), a carboxyl group (which is in the deprotonated − ...

threonine Threonine (symbol Thr or T) is an amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH form when dissolved in water), a carboxyl group (which is in the deprotonated −COO− ...

residues. They represent a subgroup of the tyrosine phosphatase family (as opposed to the serine/threonine phosphatase family). All mammals examined to date have three homologues of the ancestral Cdc25 gene (found e.g. in the

fungus A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

species '' S. pombe''), designated Cdc25A, Cdc25B, and Cdc25C. In contrast, some invertebrates harbour two (e.g., the ''

Drosophila ''Drosophila'' (), from Ancient Greek δρόσος (''drósos''), meaning "dew", and φίλος (''phílos''), meaning "loving", is a genus of fly, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or p ...

'' proteins String and Twine) or four (e.g., ''

C. elegans ''Caenorhabditis elegans'' () is a free-living transparent nematode about 1 mm in length that lives in temperate soil environments. It is the type species of its genus. The name is a blend of the Greek ''caeno-'' (recent), ''rhabditis'' ( ...

'' Cdc-25.1 - Cdc-25.4) homologues. CDC25A is required for progression from G1 to the S phase of the

cell cycle The cell cycle, or cell-division cycle, is the sequential series of events that take place in a cell (biology), cell that causes it to divide into two daughter cells. These events include the growth of the cell, duplication of its DNA (DNA re ...

, but also plays roles in later cell cycle events. In particular, it is stabilized in metaphase cells and is degraded upon metaphase exit akin to

Cyclin B Cyclin B is a member of the cyclin family. Cyclin B is a mitotic cyclin. The amount of cyclin B (which binds to Cdk1) and the activity of the cyclin B-Cdk complex rise through the cell cycle until mitosis, where they fall abruptly due to degr ...

. It is competent to activate the G1/S cyclin-dependent kinases

CDK4 Cyclin-dependent kinase 4 (CDK4), also known as cell division protein kinase 4, is an enzyme that is encoded by the ''CDK4'' gene in humans. CDK4 is a member of the cyclin-dependent kinase family, a group of serine/threonine kinases which regula ...

and

CDK2 Cyclin-dependent kinase 2, also known as cell division protein kinase 2, or Cdk2, is an enzyme that in humans is encoded by the ''CDK2'' gene. The protein encoded by this gene is a member of the cyclin-dependent kinase family of serine/threonine ...

by removing inhibitory phosphate groups from adjacent

and

residues; it can also activate Cdc2 (Cdk1), the principal mitotic Cdk.

Involvement in cancer

CDC25A is specifically degraded in response to

DNA damage DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. A weakened capacity for DNA repair is a risk factor for the development of cancer. DNA is constantly modified ...

, resulting in cell cycle arrest. Thus, this degradation represents one axis of a DNA damage checkpoint, complementing induction of

p53 p53, also known as tumor protein p53, cellular tumor antigen p53 (UniProt name), or transformation-related protein 53 (TRP53) is a regulatory transcription factor protein that is often mutated in human cancers. The p53 proteins (originally thou ...

and p21 in the inhibition of CDKs. CDC25A is considered an

oncogene An oncogene is a gene that has the potential to cause cancer. In tumor cells, these genes are often mutated, or expressed at high levels.

, as it can cooperate with oncogenic RAS to transform rodent fibroblasts, and it is overexpressed in tumours from a variety of tissues, including breast and head & neck tumours. It is a target of the E2F family of transcription factors. Therefore, its overexpression is a common consequence of dysregulation of the

- p21- Cdk axis in

carcinogenesis Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cell (biology), cells are malignant transformation, transformed into cancer cells. The process is characterized by changes at the cellular, G ...

Interactions

CDC25A has been shown to interact with: *

ASK1 Apoptosis signal-regulating kinase 1 (ASK1) also known as mitogen-activated protein kinase kinase kinase 5 (MAP3K5) is a member of MAP kinase family and as such a part of mitogen-activated protein kinase pathway. It activates c-Jun N-terminal kin ...

, *

C-Raf RAF proto-oncogene serine/threonine-protein kinase, also known as proto-oncogene c-RAF or simply c-Raf or even Raf-1, is an enzyme that in humans is genetic code, encoded by the ''RAF1'' gene. The c-Raf protein is part of the MAPK/ERK pathway, E ...

, * CHEK1, *

CCNE1 G1/S-specific cyclin-E1 is a protein that in humans is encoded by the ''CCNE1'' gene. Function The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in prot ...

, * EGFR, *

PIM1 Proto-oncogene serine/threonine-protein kinase Pim-1 is an enzyme that in humans is encoded by the ''PIM1'' gene. Pim-1 is a proto-oncogene which encodes for the serine/threonine kinase of the same name. The pim-1 oncogene was first described in ...

and *

YWHAB 14-3-3 protein beta/alpha is a protein that in humans is encoded by the ''YWHAB'' gene. Function This gene encodes a protein belonging to the 14-3-3 family of proteins, members of which mediate signal transduction by binding to phosphoserine ...

Function

Involvement in cancer

Interactions

References

External links

Further reading