Editing Inositol trisphosphate (section)

===Binding to its receptor===
[[File:IP3 moleucle.png|thumb|IP<sub>3</sub> anion with oxygen atoms (red) and the hydrogen atoms involved in docking to InsP3R (dark blue) indicated]]
The docking of IP<sub>3</sub> to its receptor, which is called the [[inositol trisphosphate receptor]] (InsP3R), was first studied using deletion [[mutagenesis]] in the early 1990s.<ref>{{Cite journal|pmid=2174351|year=1990|last1=Mignery|first1=GA|last2=Südhof|first2=TC|title=The ligand binding site and transduction mechanism in the inositol-1,4,5-triphosphate receptor|volume=9|issue=12|pages=3893–8|pmc=552159|journal=The EMBO Journal|doi=10.1002/j.1460-2075.1990.tb07609.x}}</ref> Studies focused on the [[N-terminus]] side of the IP<sub>3</sub> receptor. In 1997 researchers localized the region of the IP<sub>3</sub> receptor involved with binding of IP<sub>3</sub> to between [[amino acid]] residues 226 and 578 in 1997. Considering that IP<sub>3</sub> is a negatively charged molecule, positively charged amino acids such as [[arginine]] and [[lysine]] were believed to be involved. Two arginine residues at position 265 and 511 and one lysine residue at position 508 were found to be key in IP<sub>3</sub> docking. Using a modified form of IP<sub>3</sub>, it was discovered that all three phosphate groups interact with the receptor, but not equally. Phosphates at the 4th and 5th positions interact more extensively than the phosphate at the 1st position and the hydroxyl group at the 6th position of the inositol ring.<ref>{{cite journal|doi=10.1016/j.tibs.2004.02.010|title=IP3 receptors: The search for structure|year=2004|last1=Taylor|first1=Colin W.|last2=Da Fonseca|first2=Paula C.A.|last3=Morris|first3=Edward P.|journal=Trends in Biochemical Sciences|volume=29|issue=4|pages=210–9|pmid=15082315|url=http://www.phy.ohiou.edu/~braslavs/Biophysics/Articles/Ghanim/ip3receptors.pdf|access-date=2017-10-27|archive-date=2017-08-08|archive-url=https://web.archive.org/web/20170808142233/http://www.phy.ohiou.edu/%7Ebraslavs/Biophysics/Articles/Ghanim/ip3receptors.pdf|url-status=dead}}</ref>