growth factor receptor

{{short description|Receptor protein that binds to a growth factor protein}}

A growth factor receptor is a receptor that binds to a growth factor.{{MeshName|Growth+Factor+Receptors}} Growth factor receptors are the first stop in cells where the signaling cascade for cell differentiation and proliferation begins. Growth factors, which are ligands that bind to the receptor are the initial step to activating the growth factor receptors and tells the cell to grow and/or divide.

These receptors may use the JAK/STAT, MAP kinase, and PI3 kinase pathways.{{cite book|author1=A. V. Hoffbrand|author2=P. A. H. Moss|author3=J. E. Pettit|title=Essential haematology|url=https://books.google.com/books?id=IFFL_1YNy_oC&pg=PA6|access-date=28 November 2010|year=2006|publisher=Wiley-Blackwell|isbn=978-1-4051-3649-5|pages=6–}}

A majority of growth factor receptors consists of receptor tyrosine kinases (RTKs). There are 3 dominant receptor types that are exclusive to research : the epidermal growth factor receptor, the neurotrophin receptor, and the insulin receptors.{{Cite journal|last1=McInnes|first1=Campbell|last2=Sykes|first2=Brian D.|date=1997|title=Growth factor receptors: Structure, mechanism, and drug discovery|journal=Peptide Science|language=en|volume=43|issue=5|pages=339–366|doi=10.1002/(SICI)1097-0282(1997)43:5<339::AID-BIP2>3.0.CO;2-W|pmid=9566117|issn=1097-0282}} All growth factor receptors are membrane bound and composed of 3 general protein domains: extracellular, transmembrane, and cytoplasmic.{{Citation|title=Chapter 7 - Intercellular Signaling|date=2008-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780123704580500128|work=Medical Cell Biology (Third Edition)|pages=227–248|editor-last=Goodman|editor-first=Steven R.|publisher=Academic Press|doi=10.1016/B978-0-12-370458-0.50012-8 |language=en|isbn=978-0-12-370458-0|access-date=2020-04-29|url-access=subscription}} The extracellular domain region is where a ligand may bind, usually with very high specificity.{{Citation|last1=Kouvidi|first1=Katerina|title=Chapter Twelve - Hyaluronan/RHAMM Interactions in Mesenchymal Tumor Pathogenesis: Role of Growth Factors|date=2014-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780128000922000125|journal=Advances in Cancer Research|volume=123|pages=319–349|editor-last=Simpson|editor-first=Melanie A.|series=Hyaluronan Signaling and Turnover|publisher=Academic Press|language=en|access-date=2020-04-29|last2=Nikitovic|first2=Dragana|last3=Berdiaki|first3=Aikaterini|last4=Tzanakakis|first4=George N.|doi=10.1016/B978-0-12-800092-2.00012-5 |pmid=25081535 |editor2-last=Heldin|editor2-first=Paraskevi|url-access=subscription}} In RTKs, the binding of a ligand to the extracellular ligand binding site leads to the autophosphorylation of tyrosine residues in the intracellular domain.{{Cite journal|last1=Trenker|first1=Raphael|last2=Jura|first2=Natalia|date=2020-04-01|title=Receptor tyrosine kinase activation: From the ligand perspective|journal=Current Opinion in Cell Biology|language=en|volume=63|pages=174–185|doi=10.1016/j.ceb.2020.01.016|pmc=7813211|pmid=32114309|issn=0955-0674|doi-access=free}} These phosphorylations allow for other intracellular proteins to bind to with the phosphotyrosine-binding domain which results in a series of physiological responses within the cell.