Editing Cytosol (section)

==Function==
The cytosol is the site of multiple cell processes. Examples of these processes include [[signal transduction]] from the cell membrane to sites within the cell, such as the [[cell nucleus]],<ref>{{cite journal |author=Kholodenko BN |title=Four-dimensional organization of protein kinase signaling cascades: the roles of diffusion, endocytosis and molecular motors |journal=J. Exp. Biol. |volume=206 |issue=Pt 12 |pages=2073–82 |date=June 2003 |pmid=12756289 |doi=10.1242/jeb.00298|s2cid=18002214 |doi-access= }}</ref> or organelles.<ref>{{cite journal |vauthors=Pesaresi P, Schneider A, Kleine T, Leister D |title=Interorganellar communication |journal=Curr. Opin. Plant Biol. |volume=10 |issue=6 |pages=600–6 |date=December 2007 |pmid=17719262 |doi=10.1016/j.pbi.2007.07.007}}</ref> This compartment is also the site of many of the processes of [[cytokinesis]], after the breakdown of the [[nuclear membrane]] in [[mitosis]].<ref>{{cite journal |vauthors=Winey M, Mamay CL, O'Toole ET |title=Three-dimensional ultrastructural analysis of the Saccharomyces cerevisiae mitotic spindle |journal=J. Cell Biol. |volume=129 |issue=6 |pages=1601–15 |date=June 1995 |pmid=7790357 |pmc=2291174 |doi=10.1083/jcb.129.6.1601}}</ref> Another major function of cytosol is to transport metabolites from their site of production to where they are used. This is relatively simple for water-soluble molecules, such as amino acids, which can diffuse rapidly through the cytosol.<ref name="Verkman-2002"/> However, [[hydrophobe|hydrophobic]] molecules, such as [[fatty acid]]s or [[sterol]]s, can be transported through the cytosol by specific binding proteins, which shuttle these molecules between cell membranes.<ref>{{cite journal |author=Weisiger RA |title=Cytosolic fatty acid binding proteins catalyze two distinct steps in intracellular transport of their ligands |journal=Mol. Cell. Biochem. |volume=239 |issue=1–2 |pages=35–43 |date=October 2002 |pmid=12479566 |doi=10.1023/A:1020550405578|s2cid=9608133 }}</ref><ref>{{cite journal |vauthors=Maxfield FR, Mondal M |title=Sterol and lipid trafficking in mammalian cells |journal=Biochem. Soc. Trans. |volume=34 |issue=Pt 3 |pages=335–9 |date=June 2006 |pmid=16709155 |doi=10.1042/BST0340335}}</ref> Molecules taken into the cell by [[endocytosis]] or on their way to be [[secretion|secreted]] can also be transported through the cytosol inside [[vesicle (biology)|vesicles]],<ref>{{cite journal |author=Pelham HR |title=The Croonian Lecture 1999. Intracellular membrane traffic: getting proteins sorted |journal=Philos. Trans. R. Soc. Lond. B Biol. Sci. |volume=354 |issue=1388 |pages=1471–8 |date=August 1999 |pmid=10515003 |pmc=1692657 |doi=10.1098/rstb.1999.0491 }}</ref> which are small spheres of lipids that are moved along the cytoskeleton by [[motor protein]]s.<ref>{{cite journal |vauthors=Kamal A, Goldstein LS |title=Principles of cargo attachment to cytoplasmic motor proteins |journal=Curr. Opin. Cell Biol. |volume=14 |issue=1 |pages=63–8 |date=February 2002 |pmid=11792546 |doi=10.1016/S0955-0674(01)00295-2}}</ref>

The cytosol is the site of most metabolism in prokaryotes,<ref name="Hoppert-1999">{{cite journal |vauthors=Hoppert M, Mayer F |title=Principles of macromolecular organization and cell function in bacteria and archaea |journal=Cell Biochem. Biophys. |volume=31 |issue=3 |pages=247–84 |year=1999 |pmid=10736750 |doi=10.1007/BF02738242|s2cid=21004307 }}</ref> and a large proportion of the metabolism of eukaryotes. For instance, in mammals about half of the proteins in the cell are localized to the cytosol.<ref>{{cite journal |vauthors=Foster LJ, de Hoog CL, Zhang Y |title=A mammalian organelle map by protein correlation profiling |journal=Cell |volume=125 |issue=1 |pages=187–99 |date=April 2006 |pmid=16615899 |doi=10.1016/j.cell.2006.03.022|s2cid=32197 |doi-access=free }}</ref> The most complete data are available in yeast, where metabolic reconstructions indicate that the majority of both metabolic processes and metabolites occur in the cytosol.<ref>{{cite journal |display-authors=9 |last1=Herrgård |first1=MJ |title=A consensus yeast metabolic network reconstruction obtained from a community approach to systems biology |journal=Nature Biotechnology |volume=26 |issue=10 |pages=1155–60 |date=October 2008|doi=10.1038/nbt1492 |pmid=18846089 |last2=Swainston |first2=N |last3=Dobson |first3=P |last4=Dunn |first4=WB |last5=Arga |first5=KY |last6=Arvas |first6=M |last7=Blüthgen |first7=N |last8=Borger |first8=S |last9=Costenoble |first9=R |last10=Heinemann |first10=Matthias |last11=Hucka |first11=Michael |last12=Le Novère |first12=Nicolas |last13=Li |first13=Peter |last14=Liebermeister |first14=Wolfram |last15=Mo |first15=Monica L |last16=Oliveira |first16=Ana Paula |last17=Petranovic |first17=Dina |last18=Pettifer |first18=Stephen |last19=Simeonidis |first19=Evangelos |last20=Smallbone |first20=Kieran |last21=Spasić |first21=Irena |last22=Weichart |first22=Dieter |last23=Brent |first23=Roger |last24=Broomhead |first24=David S |last25=Westerhoff |first25=Hans V |last26=Kirdar |first26=Betül |last27=Penttilä |first27=Merja |last28=Klipp |first28=Edda |last29=Palsson |first29=Bernhard Ø |last30=Sauer |first30=Uwe |pmc=4018421}}</ref> Major metabolic pathways that occur in the cytosol in animals are [[protein biosynthesis]], the [[pentose phosphate pathway]], [[glycolysis]] and [[gluconeogenesis]].<ref>{{cite book |author1=Stryer, Lubert |author2=Berg, Jeremy Mark |author3=Tymoczko, John L. |title=Biochemistry |url=https://archive.org/details/biochemistry200100jere |url-access=registration |publisher=W.H. Freeman |location=San Francisco |year=2002 |isbn=0-7167-4684-0 |oclc=179705944}}</ref> The localization of pathways can be different in other organisms, for instance fatty acid synthesis occurs in [[chloroplast]]s in plants<ref>{{cite journal |vauthors=Ohlrogge J, Pollard M, Bao X |title=Fatty acid synthesis: from CO<sub>2</sub> to functional genomics |journal=Biochem. Soc. Trans. |volume=28 |issue=6 |pages=567–73 |date=December 2000 |pmid=11171129 |doi=10.1042/BST0280567}}</ref><ref>{{cite journal |vauthors=Ohlrogge JB, Kuhn DN, Stumpf PK |title=Subcellular localization of acyl carrier protein in leaf protoplasts of Spinacia oleracea |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=76 |issue=3 |pages=1194–8 |date=March 1979 |pmid=286305 |pmc=383216 |doi=10.1073/pnas.76.3.1194|bibcode=1979PNAS...76.1194O |doi-access=free }}</ref> and in [[apicoplast]]s in [[apicomplexa]].<ref>{{cite journal |vauthors=Goodman CD, McFadden GI |s2cid=2565225 |title=Fatty acid biosynthesis as a drug target in apicomplexan parasites |journal=Curr Drug Targets |volume=8 |issue=1 |pages=15–30 |date=January 2007 |pmid=17266528 |doi=10.2174/138945007779315579}}</ref>