Dual specificity mitogen-activated protein kinase kinase 1 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 ...
that in humans is encoded by the ''MAP2K1''
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 b ...
.
Function
The protein encoded by this gene is a member of the dual-specificity protein kinase family that acts as a
mitogen-activated protein (MAP) kinase kinase. MAP kinases, also known as
extracellular signal-regulated kinases
In molecular biology, extracellular signal-regulated kinases (ERKs) or classical MAP kinases are widely expressed protein kinase intracellular signalling molecules that are involved in functions including the regulation of meiosis, mitosis, and p ...
(ERKs), act as an
integration point for multiple biochemical signals. This protein
kinase
In biochemistry, a kinase () is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule don ...
lies upstream of
MAP kinases and stimulates the enzymatic activity of MAP kinases upon activation by a wide variety of extra- and intracellular signals. As an essential component of the
MAP kinase signal transduction pathway, this kinase is involved in many cellular processes such as
proliferation,
differentiation,
transcription regulation and development. MAP2K1 is altered in 1.05% of all human cancers.
Meiosis
The
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ...
s of
diploid
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectiv ...
organisms in natural populations are highly
polymorphic for
insertions and
deletions. During
meiosis
Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately ...
double-strand breaks (DSBs) that form within such polymorphic regions must be repaired by inter-
sister chromatid exchange
Sister chromatid exchange (SCE) is the exchange of genetic material between two identical sister chromatids.
It was first discovered by using the Giemsa staining method on one chromatid belonging to the sister chromatid complex before anaphase i ...
, rather than by
inter-homolog exchange. Molecular-level studies of recombination during budding yeast meiosis have shown that recombination events initiated by DSBs in regions that lack corresponding sequences in the
homolog
In biology, homology is similarity due to shared ancestry between a pair of structures or genes in different taxa. A common example of homologous structures is the forelimbs of vertebrates, where the wings of bats and birds, the arms of prima ...
are efficiently repaired by inter-sister chromatid recombination.
This recombination occurs with the same timing as inter-homolog recombination, but with reduced (2- to 3-fold) yields of joint molecules.
MAP2K1 is also known as MEK1 (see
Mitogen-activated protein kinase kinase
Mitogen-activated protein kinase kinase (also known as MAP2K, MEK, MAPKK) is a dual-specificity kinase enzyme which phosphorylates mitogen-activated protein kinase (MAPK).
MAP2K is classified as .
There are seven genes:
* (a.k.a. MEK1)
* ( ...
). MEK1 is a meiotic chromosome-axis-associated kinase that is thought to slow down, but not entirely block,
sister chromatid
A sister chromatid refers to the identical copies (chromatids) formed by the DNA replication of a chromosome, with both copies joined together by a common centromere. In other words, a sister chromatid may also be said to be 'one-half' of the dup ...
recombination. Loss of MEK1 allows inter-sister DSB repair and also inter-sister
Holliday junction
A Holliday junction is a branched nucleic acid structure that contains four double-stranded arms joined. These arms may adopt one of several conformations depending on buffer salt concentrations and the sequence of nucleobases closest to the j ...
intermediates to increase. Despite the normal activity of MEK1 in reducing inter-sister chromatid recombination, such recombination still occurs frequently during normal budding yeast meiosis (although not as frequently as during
mitosis
In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is maintai ...
), and up to one-third of all recombination events are between sister chromatids.
Interactions
MAP2K1 has been shown to
interact
Advocates for Informed Choice, doing business as, 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 trai ...
with
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 encoded by the ''RAF1'' gene. The c-Raf protein is part of the ERK1/2 pathway as a MAP kinase ...
,
Phosphatidylethanolamine binding protein 1
Phosphatidylethanolamine-binding protein 1 is a protein that in humans is encoded by the ''PEBP1'' gene.
Interactions
Phosphatidylethanolamine binding protein 1 has been shown to interact with:
* C-Raf,
* MAP2K1, and
* MAPK1
Mitogen-activat ...
,
[ ]MAP2K1IP1
Mitogen-activated protein kinase scaffold protein 1 is a scaffold protein that in humans is encoded by the ''MAPKSP1'' gene.
Function
The protein encoded by this gene was identified as an interacting protein that binds specifically to MAP kinas ...
,GRB10
Growth factor receptor-bound protein 10 also known as insulin receptor-binding protein Grb-IR is a protein that in humans is encoded by the ''GRB10'' gene.
Function
The product of this gene belongs to a small family of adaptor proteins that are ...
,MAPK3
Mitogen-activated protein kinase 3, also known as p44MAPK and ERK1, is an enzyme that in humans is encoded by the ''MAPK3'' gene.
Function
The protein encoded by this gene is a member of the mitogen-activated protein kinase (MAP kinase) famil ...
,MAPK1
Mitogen-activated protein kinase 1, (MAPK 1), also known as ERK2, is an enzyme that in humans is encoded by the ''MAPK1'' gene.
Function
The protein encoded by this gene is a member of the MAP kinase family. MAP kinases, also known as extrace ...
MP1
MPEG-1 Audio Layer I, commonly abbreviated to MP1, is one of three audio formats included in the MPEG-1 standard. It is a deliberately simplified version of MPEG-1 Audio Layer II (MP2), created for applications where lower compression efficiency ...
,
References
Further reading
*
*
*
*
*
*
*
External links
GeneReviews/NCBI/NIH/UW entry on Noonan syndrome
GeneReviews/NCBI/NIH/UW entry on Cardiofaciocutaneous Syndrome
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