Editing Dimerization (section)

== Biochemical dimers ==

=== Pyrimidine dimers ===
[[Pyrimidine dimers]] (also known as thymine dimers) are formed by a [[photochemical reaction]] from pyrimidine [[DNA base]]s when exposed to ultraviolet light.<ref name=":0"/> This cross-linking causes [[Mutation|DNA mutations]], which can be [[carcinogenic]], causing [[skin cancer]]s.<ref name=":0" /> When [[pyrimidine dimer]]s are present, they can block [[polymerase]]s, decreasing DNA functionality until it is repaired.<ref name=":0" />

=== Protein dimers ===
[[File:Tubulin_dimer.png|thumb|312x312px|class=skin-invert-image|Tubulin dimer]]
[[Protein dimer]]s arise from the interaction between two [[protein]]s which can interact further to form larger and more complex [[oligomer]]s.<ref name=":1">{{Cite journal |last1=Marianayagam |first1=Neelan J. |last2=Sunde |first2=Margaret |last3=Matthews |first3=Jacqueline M. |date=2004 |title=The power of two: protein dimerization in biology |url=http://dx.doi.org/10.1016/j.tibs.2004.09.006 |journal=Trends in Biochemical Sciences |volume=29 |issue=11 |pages=618–625 |doi=10.1016/j.tibs.2004.09.006 |pmid=15501681 |issn=0968-0004|url-access=subscription }}</ref> For example, [[tubulin]] is formed by the dimerization of [[Tubulin|α-tubulin]] and [[Tubulin|β-tubulin]] and this dimer can then [[Polymerization|polymerize]] further to make [[microtubule]]s.<ref>{{Cite journal |last=Cooper |first=Geoffrey M. |date=2000 |title=Microtubules |url=https://www.ncbi.nlm.nih.gov/books/NBK9932/ |journal=The Cell: A Molecular Approach. 2nd Edition |language=en}}</ref> For symmetric proteins, the larger protein complex can be broken down into smaller identical [[protein subunit]]s, which then dimerize to decrease the genetic code required to make the functional protein.<ref name=":1" />

=== G protein-coupled receptors ===
As the largest and most diverse family of [[Receptor (biochemistry)|receptors]] within the human genome, [[G protein-coupled receptor]]s (GPCR) have been studied extensively, with recent studies supporting their ability to form dimers.<ref>{{Citation |last1=Faron-Górecka |first1=Agata |title=Chapter 10 - Understanding GPCR dimerization |date=2019-01-01 |url=https://www.sciencedirect.com/science/article/pii/S0091679X18301080 |journal=Methods in Cell Biology |volume=149 |pages=155–178 |editor-last=Shukla |editor-first=Arun K. |series=G Protein-Coupled Receptors, Part B |publisher=Academic Press |language=en |doi=10.1016/bs.mcb.2018.08.005 |access-date=2022-10-27 |last2=Szlachta |first2=Marta |last3=Kolasa |first3=Magdalena |last4=Solich |first4=Joanna |last5=Górecki |first5=Andrzej |last6=Kuśmider |first6=Maciej |last7=Żurawek |first7=Dariusz |last8=Dziedzicka-Wasylewska |first8=Marta|pmid=30616817 |isbn=9780128151075 |s2cid=58577416 |url-access=subscription }}</ref> GPCR dimers include both homodimers and heterodimers formed from related members of the GPCR family.<ref>{{Cite journal |last1=Rios |first1=C. D. |last2=Jordan |first2=B. A. |last3=Gomes |first3=I. |last4=Devi |first4=L. A. |date=2001-11-01 |title=G-protein-coupled receptor dimerization: modulation of receptor function |url=https://www.sciencedirect.com/science/article/pii/S0163725801001607 |journal=Pharmacology & Therapeutics |language=en |volume=92 |issue=2 |pages=71–87 |doi=10.1016/S0163-7258(01)00160-7 |pmid=11916530 |issn=0163-7258|url-access=subscription }}</ref> While not all, some GPCRs require dimerization to function, such as [[GABAB receptor|GABA<sub>B</sub>]]-receptor, emphasizing the importance of dimers in biological systems.<ref>{{Cite journal |last=Lohse |first=Martin J |date=2010-02-01 |title=Dimerization in GPCR mobility and signaling |url=https://www.sciencedirect.com/science/article/pii/S1471489209001672 |journal=Current Opinion in Pharmacology |series=GPCR |language=en |volume=10 |issue=1 |pages=53–58 |doi=10.1016/j.coph.2009.10.007 |pmid=19910252 |issn=1471-4892|url-access=subscription }}</ref>[[File:Receptor_Tyrosine_Kinase_Dimerization.jpg|thumb|335x335px|class=skin-invert-image|Receptor tyrosine kinase dimerization]]

=== Receptor tyrosine kinase ===
Much like for G protein-coupled receptors, dimerization is essential for [[receptor tyrosine kinase]]s (RTK) to perform their function in [[signal transduction]], affecting many different cellular processes.<ref name=":2">{{Cite journal |last=Hubbard |first=Stevan R |date=1999-04-01 |title=Structural analysis of receptor tyrosine kinases |journal=Progress in Biophysics and Molecular Biology |language=en |volume=71 |issue=3 |pages=343–358 |doi=10.1016/S0079-6107(98)00047-9 |pmid=10354703 |issn=0079-6107|doi-access=free }}</ref> RTKs typically exist as monomers, but undergo a [[conformational change]] upon [[Ligand (biochemistry)|ligand]] binding, allowing them to dimerize with nearby RTKs.<ref>{{Cite journal |last1=Lemmon |first1=Mark A. |last2=Schlessinger |first2=Joseph |date=2010-06-25 |title=Cell Signaling by Receptor Tyrosine Kinases |journal=Cell |language=English |volume=141 |issue=7 |pages=1117–1134 |doi=10.1016/j.cell.2010.06.011 |issn=0092-8674 |pmc=2914105 |pmid=20602996}}</ref><ref>{{Cite journal |last1=Lemmon |first1=Mark A. |last2=Schlessinger |first2=Joseph |last3=Ferguson |first3=Kathryn M. |date=2014-04-01 |title=The EGFR Family: Not So Prototypical Receptor Tyrosine Kinases |journal=Cold Spring Harbor Perspectives in Biology |language=en |volume=6 |issue=4 |pages=a020768 |doi=10.1101/cshperspect.a020768 |issn=1943-0264 |pmid=24691965|pmc=3970421 |doi-access=free }}</ref> The dimerization activates the [[cytoplasm]]ic [[kinase]] [[Protein domain|domains]] that are responsible for further [[signal transduction]].<ref name=":2" />