Editing Zinc (section)

===Other proteins===
Zinc serves a purely structural role in [[zinc finger]]s, twists and clusters.<ref name="Cotton1997p628">{{harvnb|Cotton et al.|1999|p=628}}</ref> Zinc fingers form parts of some [[transcription factor]]s, which are proteins that recognize [[DNA sequence|DNA base sequences]] during the replication and transcription of [[DNA]]. Each of the nine or ten {{chem|Zn|2+}} ions in a zinc finger helps maintain the finger's structure by coordinately binding to four [[amino acid]]s in the transcription factor.<ref name="Greenwood1997p1225" />

In [[blood plasma]], zinc is bound to and transported by [[albumin]] (60%, low-affinity) and [[transferrin]] (10%).<ref name="Rink2000" /> Because transferrin also transports iron, excessive iron reduces zinc absorption, and vice versa. A similar antagonism exists with copper.<ref name="Whitney2005">{{Cite book|first=Eleanor Noss|last=Whitney|author2=Rolfes, Sharon Rady |date=2005|title=Understanding Nutrition|pages=447–450|edition=10th|publisher=Thomson Learning|isbn=978-1-4288-1893-4}}</ref> The concentration of zinc in blood plasma stays relatively constant regardless of zinc intake.<ref name="DRI" /> Cells in the salivary gland, prostate, immune system, and intestine use [[Cell signaling|zinc signaling]] to communicate with other cells.<ref>{{Cite journal|last=Hershfinkel|first=M|author2=Silverman WF |author3=Sekler I |title=The Zinc Sensing Receptor, a Link Between Zinc and Cell Signaling |journal=Molecular Medicine|volume=13|date=2007|doi= 10.2119/2006-00038.Hershfinkel |pmid=17728842|issue=7–8|pmc=1952663|pages=331–336}}</ref>

Zinc may be held in [[metallothionein]] reserves within microorganisms or in the intestines or liver of animals.<ref name="Cotton1999p629">{{harvnb|Cotton et al.|1999|p=629}}</ref> Metallothionein in intestinal cells is capable of adjusting absorption of zinc by 15–40%.<ref name="Blake2007">{{Cite book|title=Vitamins and Minerals Demystified|last=Blake|first=Steve|publisher=McGraw-Hill Professional|date=2007|isbn=978-0-07-148901-0|page=242}}</ref> However, inadequate or excessive zinc intake can be harmful; excess zinc particularly impairs copper absorption because metallothionein absorbs both metals.<ref name="Fosmire1990" />

The human [[dopamine transporter]] contains a [[affinity (pharmacology)|high affinity]] extracellular zinc [[binding site]] which, upon zinc binding, inhibits dopamine [[reuptake]] and amplifies [[amphetamine]]-induced [[neurotransmitter efflux|dopamine efflux]] ''[[in vitro]]''.<ref name="Zinc binding sites + ADHD review">{{cite journal | vauthors = Krause J | title = SPECT and PET of the dopamine transporter in attention-deficit/hyperactivity disorder | journal = Expert Rev. Neurother. |volume = 8 |issue = 4 |pages = 611–625 |date = 2008 | pmid = 18416663 | doi = 10.1586/14737175.8.4.611| s2cid = 24589993 }}</ref><ref name="Review - cites 2002 amph-zinc primary study">{{cite journal | vauthors = Sulzer D | title = How addictive drugs disrupt presynaptic dopamine neurotransmission |journal = Neuron |volume = 69 |issue = 4 |pages = 628–649 | date =2011 |pmid = 21338876 |pmc = 3065181 |doi = 10.1016/j.neuron.2011.02.010}}</ref><ref name="Primary 2002 amph-zinc study">{{cite journal | vauthors = Scholze P, Nørregaard L, Singer EA, Freissmuth M, Gether U, Sitte HH | title = The role of zinc ions in reverse transport mediated by monoamine transporters | journal = J. Biol. Chem. | volume = 277 | issue = 24 | pages = 21505–21513 | date = 2002 | pmid = 11940571 | doi = 10.1074/jbc.M112265200 | quote = The human dopamine transporter (hDAT) contains an endogenous high affinity Zn<sup>2+</sup> binding site with three coordinating residues on its extracellular face (His193, His375, and Glu396).&nbsp;... Thus, when Zn<sup>2+</sup> is co-released with glutamate, it may greatly augment the efflux of dopamine.| doi-access = free }}</ref> The human [[serotonin transporter]] and [[norepinephrine transporter]] do not contain zinc binding sites.<ref name="Primary 2002 amph-zinc study" /> Some [[EF hand|EF-hand]] [[Calcium-binding protein|calcium binding proteins]] such as [[S100 protein|S100]] or [[Neuronal calcium sensor-1|NCS-1]] are also able to bind zinc ions.<ref>{{cite journal |last1=Tsvetkov |first1=PO |last2=Roman |first2=AY |last3=Baksheeva |first3=VE |last4=Nazipova |first4=AA |last5=Shevelyova |first5=MP |last6=Vladimirov |first6=VI |last7=Buyanova |first7=MF |last8=Zinchenko |first8=DV |last9=Zamyatnin AA |first9=Jr |last10=Devred |first10=F |last11=Golovin |first11=AV |last12=Permyakov |first12=SE |last13=Zernii |first13=EY |title=Functional Status of Neuronal Calcium Sensor-1 Is Modulated by Zinc Binding. |journal=Frontiers in Molecular Neuroscience |date=2018 |volume=11 |pages=459 |doi=10.3389/fnmol.2018.00459 |pmid=30618610|pmc=6302015 |doi-access=free }}</ref>