Class I PI 3-kinases are a subgroup of the enzyme family,
phosphoinositide 3-kinase
Phosphoinositide 3-kinases (PI3Ks), also called phosphatidylinositol 3-kinases, are a family of enzymes involved in cellular functions such as cell growth, proliferation, differentiation, motility, survival and intracellular trafficking, which i ...
that possess a common protein domain structure, substrate specificity, and method of activation. Class I PI 3-kinases are further divided into two subclasses, class IA PI 3-kinases and class IB PI 3-kinases.
Class IA PI 3-kinases
Class IA PI 3-kinases are activated by
receptor tyrosine kinases (RTKs).
There are three catalytic subunits that are classified as class IA PI 3-kinases:
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p110α
*
p110β
Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta isoform is an enzyme that in humans is encoded by the ''PIK3CB'' gene.
Phosphoinositide 3-kinases (PI3Ks) phosphorylate the 3-prime OH position of the inositol ring of inositol ...
*
p110δ
There are currently five regulatory subunits that are known to associate with class IA PI 3-kinases catalytic subunits:
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p85α
Phosphatidylinositol 3-kinase regulatory subunit alpha is an enzyme that in humans is encoded by the ''PIK3R1'' gene.
Function
Phosphatidylinositol 3-kinase phosphorylates the inositol ring of phosphatidylinositol at the 3-prime position. The ...
and
p85β
Phosphatidylinositol 3-kinase regulatory subunit beta is an enzyme that in humans is encoded by the ''PIK3R2'' gene.
A recent study on gene expression indicated that the PIK3R2 gene might have a key role in pan-cancer prognosis.
Interactions
...
*
p55α and
p55γ
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p50α
P5 may refer to:
In science and technology
* 311P/PANSTARRS, also known as P/2013 P5 (PANSTARRS), an asteroid discovered by the Pan-STARRS telescope on 27 August 2013
* P5 Truss Segment, an element of the International Space Station
* Period ...
Class IB PI 3-kinases
Class IB PI 3-kinases are activated by
G-protein-coupled receptors
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related p ...
(GPCRs).
The only known class IB PI 3-kinase catalytic subunit is
p110γ
Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma isoform is an enzyme that in humans is encoded by the ''PIK3CG'' gene.
Function
This gene encodes a protein that belongs to the pi3/pi4-kinase family of proteins. The gene p ...
.
There are two known regulatory subunits for p110γ:
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p101
*p84/
p87PIKAP
Within molecular biology, molecular and cell biology, p87PIKAP is a regulatory subunit of the type IB Phosphoinositide 3-Kinase p110γ that is highly expressed in the heart and is present in dendritic cells, macrophages, and neutrophils.
It is als ...
.
See also
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Phosphoinositide 3-kinase#Class I
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Phosphoinositide 3-kinase inhibitor
Phosphoinositide 3-kinase inhibitors (PI3K inhibitors) are a class of medical drugs that are mainly used to treat advanced cancers. They function by inhibiting one or more of the phosphoinositide 3-kinase (PI3K) enzymes, which are part of the PI3 ...
References
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EC 2.7.1
{{Cell-biology-stub