{{Short description|Group of enzymes}} '''Class I PI 3-kinases''' are a subgroup of the enzyme family, phosphoinositide 3-kinase 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:{{citation needed|date=January 2017}} *p110α *p110β *p110δ <!-- *p110γ -- since listed in ''Class IB PI 3-kinases'' below - and see Phosphoinositide_3-kinase#Class_I -->
There are currently five regulatory subunits that are known to associate with class IA PI 3-kinases catalytic subunits:{{citation needed|date=January 2017}}
*p85α and p85β *p55α and p55γ *p50α
==Class IB PI 3-kinases== Class IB PI 3-kinases are activated by G-protein-coupled receptors (GPCRs).
The only known class IB PI 3-kinase catalytic subunit is p110γ.
There are two known regulatory subunits for p110γ: *p101 *p84/ p87PIKAP.
==See also== * Phosphoinositide 3-kinase#Class I * Phosphoinositide 3-kinase inhibitor
==References== *{{cite journal |author=Stein RC |title=Prospects for phosphoinositide 3-kinase inhibition as a cancer treatment |journal=Endocr. Relat. Cancer |volume=8 |issue=3 |pages=237–48 |date=September 2001 |pmid=11566615 |doi=10.1677/erc.0.0080237 |url=http://erc.endocrinology-journals.org/cgi/reprint/8/3/237 |citeseerx=10.1.1.324.8135 |s2cid=568427 |access-date=2008-09-24 |archive-url=https://web.archive.org/web/20080521221607/http://erc.endocrinology-journals.org/cgi/reprint/8/3/237 |archive-date=2008-05-21 |url-status=dead }} *{{cite journal |vauthors=Foster FM, Traer CJ, Abraham SM, Fry MJ |title=The phosphoinositide (PI) 3-kinase family |journal=J. Cell Sci. |volume=116 |issue=Pt 15 |pages=3037–40 |date=August 2003 |pmid=12829733 |doi=10.1242/jcs.00609 |doi-access=free }} *{{cite journal|vauthors=Vanhaesebroeck B, Waterfield MD |title=Signaling by distinct classes of phosphoinositide 3-kinases |journal=Exp. Cell Res. |volume=253 |issue=1 |pages=239–54 |date=November 1999 |pmid=10579926 |doi=10.1006/excr.1999.4701 |url=http://www.ludwig.ucl.ac.uk/cellsig_pdf/VanhaesebroeckB1999c.pdf |url-status=dead |archive-url=https://web.archive.org/web/20060102214308/http://www.ludwig.ucl.ac.uk/cellsig_pdf/VanhaesebroeckB1999c.pdf |archive-date=January 2, 2006 }}
{{Kinases}} {{Enzymes}} {{Portal bar|Biology|border=no}}
Category:EC 2.7.1
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