Mitogen-activated protein kinase kinase (also known as MAP2K, MEK, MAPKK) is a
dual-specificity kinase
In biochemistry, a dual-specificity kinase () is a kinase that can act as both tyrosine kinase and serine/threonine kinase.
MEKs, involved in MAP pathways, are principal examples of dual-specificity kinases. Other common examples include:
* AD ...
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
which
phosphorylates
In biochemistry, phosphorylation is described as the "transfer of a phosphate group" from a donor to an acceptor. A common phosphorylating agent (phosphate donor) is ATP and a common family of acceptor are alcohols:
:
This equation can be writt ...
mitogen-activated protein kinase
A mitogen-activated protein kinase (MAPK or MAP kinase) is a type of serine/threonine-specific protein kinases involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock and proinflamma ...
(MAPK).
MAP2K is classified as .
There are seven genes:
* (a.k.a.
MEK1
Dual specificity mitogen-activated protein kinase kinase 1 is an enzyme that in humans is encoded by the ''MAP2K1'' gene.
Function
The protein encoded by this gene is a member of the dual-specificity protein kinase family that acts as a mit ...
)
* (a.k.a.
MEK2
Dual specificity mitogen-activated protein kinase kinase 2 is an enzyme that in humans is encoded by the ''MAP2K2'' gene. It is more commonly known as MEK2, but has many alternative names including CFC4, MKK2, MAPKK2 and PRKMK2.
Function
The ...
)
* (a.k.a.
MKK3
Dual specificity mitogen-activated protein kinase kinase 3 is an enzyme that in humans is encoded by the ''MAP2K3'' gene.
The protein encoded by this gene is a dual specificity protein kinase that belongs to the MAP kinase kinase family. This k ...
)
* (a.k.a.
MKK4
Dual-specificity mitogen-activated protein kinase kinase 4 is an enzyme that in humans is encoded by the ''MAP2K4'' gene.
''MAP2K4'' encodes a dual-specificity kinase that belongs to the Ser/Thr protein kinase family. MAP2K4 phosphorylates M ...
)
* (a.k.a.
MKK5
Dual specificity mitogen-activated protein kinase kinase 5 is an enzyme that in humans is encoded by the ''MAP2K5'' gene.
Function
The protein encoded by this gene is a dual specificity protein kinase that belongs to the MAP kinase kinase fami ...
)
* (a.k.a.
MKK6
Dual specificity mitogen-activated protein kinase kinase 6 also known as MAP kinase kinase 6 (MAPKK 6) or MAPK/ERK kinase 6 is an enzyme that in humans is encoded by the ''MAP2K6'' gene, on chromosome 17.
Function
MAPKK 6 is a member of the ...
)
* (a.k.a.
MKK7
Dual specificity mitogen-activated protein kinase kinase 7, also known as MAP kinase kinase 7 or MKK7, is an enzyme that in humans is encoded by the ''MAP2K7'' gene. This protein is a member of the MKK, mitogen-activated protein kinase kinase fam ...
)
The activators of
p38 (MKK3 and MKK6),
JNK
c-Jun N-terminal kinases (JNKs), were originally identified as kinases that bind and phosphorylate c-Jun on Ser-63 and Ser-73 within its transcriptional activation domain. They belong to the mitogen-activated protein kinase family, and are r ...
(MKK4 and MKK7), and
ERK (MEK1 and MEK2) define independent
MAP kinase
A mitogen-activated protein kinase (MAPK or MAP kinase) is a type of serine/threonine-specific protein kinases involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock and proinflammato ...
signal transduction pathways. The acronym MEK derives from MAPK/ERK Kinase.
Role in melanoma
MEK is a member of the MAPK signaling cascade that is activated in melanoma.
When MEK is inhibited, cell proliferation is blocked and
apoptosis
Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...
(controlled cell death) is induced.
See also
*
Signal transduction
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a biochemical cascade, series of molecular events. Proteins responsible for detecting stimuli are generally termed receptor (biology), rece ...
*
MAP kinase
A mitogen-activated protein kinase (MAPK or MAP kinase) is a type of serine/threonine-specific protein kinases involved in directing cellular responses to a diverse array of stimuli, such as mitogens, osmotic stress, heat shock and proinflammato ...
*
MAP kinase kinase kinase
Mitogen Activated Protein (MAP) kinase kinase kinase (MAPKKK, MKKK, M3K, or, MAP3K) is a serine/threonine-specific protein kinase which acts upon MAP kinase kinase. Subsequently, MAP kinase kinase activates MAP kinase. Several types of MAPKKK ca ...
*
MAP kinase kinase kinase kinase Mitogen-activated protein kinase kinase kinase kinase (MAP4K) is a family of proteins involved in cellular signal transduction.
* MAP4K1 (aka HPK1)
* MAP4K2 (aka GCK)
* MAP4K3 (aka GLK)
* MAP4K4 (aka HGK)
* MAP4K5 (aka KHS)
* MAP4K6 (aka MINK)
...
References
External links
*
Protein kinases
EC 2.7.12
Genes associated with cancer
{{Protein-stub