EIF2S1: Difference between revisions

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{{Infobox_gene}}
{{PBB_Controls
'''Eukaryotic translation initiation factor 2 subunit 1 (eIF2α)''' is a [[protein]] that in humans is encoded by the ''EIF2S1'' [[gene]].<ref name="pmid2948954">{{cite journal | vauthors = Ernst H, Duncan RF, Hershey JW | title = Cloning and sequencing of complementary DNAs encoding the alpha-subunit of translational initiation factor eIF-2. Characterization of the protein and its messenger RNA | journal = J Biol Chem | volume = 262 | issue = 3 | pages = 1206–12 |date=Mar 1987 | pmid = 2948954 | pmc =  | doi =  }}</ref><ref name="entrez">{{cite web|title=Entrez Gene: EIF2S1 eukaryotic translation initiation factor 2, subunit 1 alpha, 35kDa|url=https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1965|accessdate=2010-10-05|publisher= [[National Center for Biotechnology Information]], U.S. National Library of Medicine}}</ref>
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==Function==
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The [[protein]] encoded by this gene is the alpha (α) subunit of the [[eukaryotic initiation factor|translation initiation factor]] [[eIF2]] complex which catalyzes an early regulated step of [[protein synthesis]] initiation, promoting the binding of the initiator tRNA (Met-tRNA<sub>i</sub><sup>Met</sup>) to [[40S]] [[ribosome|ribosomal]] subunits. Binding occurs as a ternary complex of [[Methionine|methionyl]]-[[Transfer RNA|tRNA]], [[eIF2]], and [[Guanosine triphosphate|GTP]]. eIF2 is composed of 3 nonidentical subunits, alpha (α, 36 kD, this article), [[EIF2S2|beta]] (β, 38 kD), and  [[EIF2S3|gamma]] (γ, 52 kD). The rate of formation of the ternary complex is modulated by the [[phosphorylation]] state of eIF2α.<ref name="entrez"/>
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==Clinical significance==
After reperfusion following brain [[ischemia]], there is inhibition of neuron protein synthesis due to phosphorylation of eIF2α. There is colocalization between phosphorylated eIF2α and [[cytosol]]ic [[cytochrome c]], which is released from [[mitochondria]] in [[apoptosis]]. Phosphorylated Eif2-alpha appeared before cytochrome c release, suggesting that phosphorylation of eIF2α triggers cytochrome c release during apoptotic cell death.<ref name="pmid12687390">{{cite journal | vauthors = Page AB, Owen CR, Kumar R, Miller JM, Rafols JA, White BC, DeGracia DJ, Krause GS | title = Persistent eIF2alpha(P) is colocalized with cytoplasmic cytochrome c in vulnerable hippocampal neurons after 4 hours of reperfusion following 10-minute complete brain ischemia | journal = Acta Neuropathol. | volume = 106 | issue = 1 | pages = 8–16 |date=July 2003 | pmid = 12687390 | doi = 10.1007/s00401-003-0693-2 | url =  }}</ref>
 
Mice [[heterozygous]] for the S51A [[mutation]] become obese and [[diabetes|diabetic]] on a high-fat diet. [[Glucose intolerance]] resulted from reduced [[insulin]] secretion, defective transport of proinsulin, and a reduced number of insulin granules in [[beta cell]]s. Hence proper functioning of eIF2α appears essential for preventing diet-induced [[diabetes mellitus type 2|type II diabetes]].<ref name="pmid15980866">{{cite journal | vauthors = Scheuner D, Vander Mierde D, Song B, Flamez D, Creemers JW, Tsukamoto K, Ribick M, Schuit FC, Kaufman RJ | title = Control of mRNA translation preserves endoplasmic reticulum function in beta cells and maintains glucose homeostasis | journal = Nat. Med. | volume = 11 | issue = 7 | pages = 757–764 |date=July 2005 | pmid = 15980866 | doi = 10.1038/nm1259 | url = }}</ref>


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==Dephosphorylation inhibitors==
{{GNF_Protein_box
[[Salubrinal]] is a selective inhibitor of enzymes that dephosphorylate eIF2α.<ref name="pmid15705855">{{cite journal | vauthors = Boyce M, Bryant KF, Jousse C, Long K, Harding HP, Scheuner D, Kaufman RJ, Ma D, Coen DM, Ron D, Yuan J | title = A selective inhibitor of eIF2alpha dephosphorylation protects cells from ER stress | journal = Science | volume = 307 | issue = 5711 | pages = 935–939 |date=February 2005 | pmid = 15705855 | doi = 10.1126/science.1101902 | url =  }}</ref> Salubrinal also blocks eIF2α dephosphorylation by a [[herpes simplex virus]] protein and inhibits viral replication. eIF2α phosphorylation is cytoprotective during [[endoplasmic reticulum]] stress.<ref name="pmid10882126">{{cite journal | vauthors = Harding HP, Zhang Y, Bertolotti A, Zeng H, Ron D | title = Perk is essential for translational regulation and cell survival during the unfolded protein response | journal = Mol. Cell | volume = 5 | issue = 5 | pages = 897–904 |date=May 2000 | pmid = 10882126 | doi = 10.1016/S1097-2765(00)80330-5 | url =   }}</ref><ref name="pmid11430820">{{cite journal | vauthors = Scheuner D, Song B, McEwen E, Liu C, Laybutt R, Gillespie P, Saunders T, Bonner-Weir S, Kaufman RJ | title = Translational control is required for the unfolded protein response and in vivo glucose homeostasis | journal = Mol. Cell | volume = 7 | issue = 6 | pages = 1165–1176 |date=June 2001 | pmid = 11430820 | doi = 10.1016/S1097-2765(01)00265-9| url = http://linkinghub.elsevier.com/retrieve/pii/S1097-2765(01)00265-9 }}</ref>
| image = PBB_Protein_EIF2S1_image.jpg
| image_source = [[Protein_Data_Bank|PDB]] rendering based on 1kl9.
| PDB = {{PDB2|1kl9}}, {{PDB2|1q8k}}
| Name = Eukaryotic translation initiation factor 2, subunit 1 alpha, 35kDa
| HGNCid = 3265
| Symbol = EIF2S1
| AltSymbols =; EIF-2; EIF-2A; EIF-2alpha; EIF2; EIF2A
| OMIM = 603907
| ECnumber =
| Homologene = 3020
| MGIid = 95299
| GeneAtlas_image1 = PBB_GE_EIF2S1_201142_at_tn.png
| GeneAtlas_image2 = PBB_GE_EIF2S1_201143_s_at_tn.png
| GeneAtlas_image3 = PBB_GE_EIF2S1_201144_s_at_tn.png
  | Function = {{GNF_GO|id=GO:0003723 |text = RNA binding}} {{GNF_GO|id=GO:0003743 |text = translation initiation factor activity}} {{GNF_GO|id=GO:0005515 |text = protein binding}}
| Component = {{GNF_GO|id=GO:0005634 |text = nucleus}} {{GNF_GO|id=GO:0005737 |text = cytoplasm}} {{GNF_GO|id=GO:0005844 |text = polysome}} {{GNF_GO|id=GO:0005850 |text = eukaryotic translation initiation factor 2 complex}} {{GNF_GO|id=GO:0005851 |text = eukaryotic translation initiation factor 2B complex}}
| Process = {{GNF_GO|id=GO:0006417 |text = regulation of translation}} {{GNF_GO|id=GO:0043558 |text = regulation of translation initiation in response to stress}}
| Orthologs = {{GNF_Ortholog_box
    | Hs_EntrezGene = 1965
    | Hs_Ensembl = ENSG00000134001
    | Hs_RefseqProtein = NP_004085
    | Hs_RefseqmRNA = NM_004094
    | Hs_GenLoc_db =
    | Hs_GenLoc_chr = 14
    | Hs_GenLoc_start = 66896787
    | Hs_GenLoc_end = 66922986
    | Hs_Uniprot = P05198
    | Mm_EntrezGene = 13665
    | Mm_Ensembl = 
    | Mm_RefseqmRNA = NM_026114
    | Mm_RefseqProtein = NP_080390
    | Mm_GenLoc_db = 
    | Mm_GenLoc_chr = 
    | Mm_GenLoc_start = 
    | Mm_GenLoc_end = 
    | Mm_Uniprot = 
  }}
}}
'''Eukaryotic translation initiation factor 2, subunit 1 alpha, 35kDa''', also known as '''EIF2S1''', is a human [[gene]].<ref name="entrez">{{cite web | title = Entrez Gene: EIF2S1 eukaryotic translation initiation factor 2, subunit 1 alpha, 35kDa| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1965| accessdate = }}</ref>


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==See also==
{{PBB_Summary
* [[eIF2]]
| section_title =  
| summary_text = The translation initiation factor eIF2 catalyzes the first regulated step of protein synthesis initiation, promoting the binding of the initiator tRNA to 40S ribosomal subunits. Binding occurs as a ternary complex of methionyl-tRNA, eIF2, and GTP. eIF2 is composed of 3 nonidentical subunits, alpha (36 kD), beta (38 kD, MIM 603908), and gamma (52 kD, MIM 300161). The rate of formation of the ternary complex is modulated by the phosphorylation state of eIF2-alpha (Ernst et al., 1987).[supplied by OMIM]<ref name="entrez">{{cite web | title = Entrez Gene: EIF2S1 eukaryotic translation initiation factor 2, subunit 1 alpha, 35kDa| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1965| accessdate = }}</ref>
}}


==References==
==References==
{{reflist|2}}
{{Reflist|2}}
 
==Further reading==
==Further reading==
{{refbegin | 2}}
{{refbegin | 2}}
{{PBB_Further_reading  
{{PBB_Further_reading  
| citations =  
| citations =  
*{{cite journal  | author=Hershey JW |title=Translational control in mammalian cells. |journal=Annu. Rev. Biochem. |volume=60 |issue=  |pages= 717-55 |year= 1991 |pmid= 1883206 |doi= 10.1146/annurev.bi.60.070191.003441 }}
*{{cite journal  | author=Hershey JW |title=Translational control in mammalian cells |journal=Annu. Rev. Biochem. |volume=60 |issue=  |pages= 717–755 |year= 1991 |pmid= 1883206 |doi= 10.1146/annurev.bi.60.070191.003441 }}
*{{cite journal  | author=Mao X, Green JM, Safer B, ''et al.'' |title=Regulation of translation initiation factor gene expression during human T cell activation. |journal=J. Biol. Chem. |volume=267 |issue= 28 |pages= 20444-50 |year= 1992 |pmid= 1400363 |doi= }}
*{{cite journal  | author=Mao X |title=Regulation of translation initiation factor gene expression during human T cell activation |journal=J. Biol. Chem. |volume=267 |issue= 28 |pages= 20444–50 |year= 1992 |pmid= 1400363 |doi=  |name-list-format=vanc| author2=Green JM  | author3=Safer B  | display-authors=| last4=Lindsten  | first4=| last5=Frederickson  | first5=RM  | last6=Miyamoto  | first6=S  | last7=Sonenberg  | first7=N  | last8=Thompson  | first8=CB }}
*{{cite journal | author=Mellor H, Proud CG |title=A synthetic peptide substrate for initiation factor-2 kinases. |journal=Biochem. Biophys. Res. Commun. |volume=178 |issue= 2 |pages= 430-7 |year= 1991 |pmid= 1677563 |doi=  }}
*{{cite journal  | vauthors=Mellor H, Proud CG |title=A synthetic peptide substrate for initiation factor-2 kinases |journal=Biochem. Biophys. Res. Commun. |volume=178 |issue= 2 |pages= 430–437 |year= 1991 |pmid= 1677563 |doi=10.1016/0006-291X(91)90125-Q }}
*{{cite journal  | author=Green SR, Spalding A, Ashford T, ''et al.'' |title=Synthesis of human initiation factor-2 alpha in Saccharomyces cerevisiae. |journal=Gene |volume=108 |issue= 2 |pages= 253-8 |year= 1992 |pmid= 1748310 |doi=  }}
*{{cite journal  | author=Green SR |title=Synthesis of human initiation factor-2 alpha in Saccharomyces cerevisiae |journal=Gene |volume=108 |issue= 2 |pages= 253–258 |year= 1992 |pmid= 1748310 |doi=10.1016/0378-1119(91)90441-D |name-list-format=vanc| author2=Spalding A  | author3=Ashford T  | display-authors=3  | last4=Proud  | first4=| last5=Tuite  | first5=M }}
*{{cite journal  | author=Kramer G |title=Two phosphorylation sites on eIF-2 alpha. |journal=FEBS Lett. |volume=267 |issue= 2 |pages= 181-2 |year= 1990 |pmid= 2116318 |doi= }}
*{{cite journal  | author=Kramer G |title=Two phosphorylation sites on eIF-2 alpha |journal=FEBS Lett. |volume=267 |issue= 2 |pages= 181–182 |year= 1990 |pmid= 2116318 |doi=10.1016/0014-5793(90)80919-A }}
*{{cite journal | author=Ernst H, Duncan RF, Hershey JW |title=Cloning and sequencing of complementary DNAs encoding the alpha-subunit of translational initiation factor eIF-2. Characterization of the protein and its messenger RNA. |journal=J. Biol. Chem. |volume=262 |issue= 3 |pages= 1206-12 |year= 1987 |pmid= 2948954 |doi=  }}
*{{cite journal  | author=Kato S |title=Construction of a human full-length cDNA bank |journal=Gene |volume=150 |issue= 2 |pages= 243–250 |year= 1995 |pmid= 7821789 |doi=10.1016/0378-1119(94)90433-2 |name-list-format=vanc| author2=Sekine S  | author3=Oh SW  | display-authors=| last4=Namsoon  | first4=| last5=Yuri  | first5=U  | last6=Naoto  | first6=A  | last7=Midori  | first7=| last8=Takashi  | first8=A }}
*{{cite journal  | author=Kato S, Sekine S, Oh SW, ''et al.'' |title=Construction of a human full-length cDNA bank. |journal=Gene |volume=150 |issue= 2 |pages= 243-50 |year= 1995 |pmid= 7821789 |doi=  }}
*{{cite journal  | author=Ray MK |title=Characteristics of the eukaryotic initiation factor 2 associated 67-kDa polypeptide |journal=Biochemistry |volume=32 |issue= 19 |pages= 5151–5159 |year= 1993 |pmid= 8098621 |doi=10.1021/bi00070a026 |name-list-format=vanc| author2=Chakraborty A | author3=Datta B | display-authors=3 | last4=Chattopadhyay  | first4=Ansuman  | last5=Saha | first5=Debabrata  | last6=Bose  | first6=Avirup  | last7=Kinzy | first7=Terry G.  | last8=Wu  | first8=Shiyong  | last9=Hileman  | first9=Ronald E. }}
*{{cite journal  | author=Ray MK, Chakraborty A, Datta B, ''et al.'' |title=Characteristics of the eukaryotic initiation factor 2 associated 67-kDa polypeptide. |journal=Biochemistry |volume=32 |issue= 19 |pages= 5151-9 |year= 1993 |pmid= 8098621 |doi=  }}
*{{cite journal  | author=Dever TE |title=Mammalian eukaryotic initiation factor 2 alpha kinases functionally substitute for GCN2 protein kinase in the GCN4 translational control mechanism of yeast |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=90 |issue= 10 |pages= 4616–4620 |year= 1993 |pmid= 8099443 |doi=10.1073/pnas.90.10.4616 | pmc=46563 |name-list-format=vanc| author2=Chen JJ  | author3=Barber GN  | display-authors=| last4=Cigan  | first4=AM  | last5=Feng  | first5=| last6=Donahue  | first6=TF  | last7=London | first7=IM | last8=Katze  | first8=MG  | last9=Hinnebusch  | first9=AG  }}
*{{cite journal  | author=Dever TE, Chen JJ, Barber GN, ''et al.'' |title=Mammalian eukaryotic initiation factor 2 alpha kinases functionally substitute for GCN2 protein kinase in the GCN4 translational control mechanism of yeast. |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=90 |issue= 10 |pages= 4616-20 |year= 1993 |pmid= 8099443 |doi=  }}
*{{cite journal | author=Barber GN |title=Translational regulation by the interferon-induced double-stranded-RNA-activated 68-kDa protein kinase |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=90 |issue= 10 |pages= 4621–4625 |year= 1993 |pmid= 8099444 |doi=10.1073/pnas.90.10.4621  | pmc=46564  |name-list-format=vanc| author2=Wambach M  | author3=Wong ML  | display-authors=| last4=Dever | first4=TE | last5=Hinnebusch  | first5=AG  | last6=Katze  | first6=MG  }}
*{{cite journal  | author=Barber GN, Wambach M, Wong ML, ''et al.'' |title=Translational regulation by the interferon-induced double-stranded-RNA-activated 68-kDa protein kinase. |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=90 |issue= 10 |pages= 4621-5 |year= 1993 |pmid= 8099444 |doi=  }}
*{{cite journal | vauthors=Miyamoto S, Chiorini JA, Urcelay E, Safer B |title=Regulation of gene expression for translation initiation factor eIF-2 alpha: importance of the 3' untranslated region |journal=Biochem. J. |volume=315 |issue=  3|pages= 791–8 |year= 1996 |pmid= 8645159 |doi= | pmc=1217276 }}
*{{cite journal | author=Miyamoto S, Chiorini JA, Urcelay E, Safer B |title=Regulation of gene expression for translation initiation factor eIF-2 alpha: importance of the 3' untranslated region. |journal=Biochem. J. |volume=315 ( Pt 3) |issue=  |pages= 791-8 |year= 1996 |pmid= 8645159 |doi= }}
*{{cite journal  | vauthors=Yang W, Hinnebusch AG |title=Identification of a regulatory subcomplex in the guanine nucleotide exchange factor eIF2B that mediates inhibition by phosphorylated eIF2 |journal=Mol. Cell. Biol. |volume=16 |issue= 11 |pages= 6603–16 |year= 1996 |pmid= 8887689 |doi= | pmc=231662 }}
*{{cite journal | author=Yang W, Hinnebusch AG |title=Identification of a regulatory subcomplex in the guanine nucleotide exchange factor eIF2B that mediates inhibition by phosphorylated eIF2. |journal=Mol. Cell. Biol. |volume=16 |issue= 11 |pages= 6603-16 |year= 1996 |pmid= 8887689 |doi=  }}
*{{cite journal  | vauthors=Brand SR, Kobayashi R, Mathews MB |title=The Tat protein of human immunodeficiency virus type 1 is a substrate and inhibitor of the interferon-induced, virally activated protein kinase, PKR |journal=J. Biol. Chem. |volume=272 |issue= 13 |pages= 8388–8395 |year= 1997 |pmid= 9079663 |doi=10.1074/jbc.272.13.8388 }}
*{{cite journal | author=Brand SR, Kobayashi R, Mathews MB |title=The Tat protein of human immunodeficiency virus type 1 is a substrate and inhibitor of the interferon-induced, virally activated protein kinase, PKR. |journal=J. Biol. Chem. |volume=272 |issue= 13 |pages= 8388-95 |year= 1997 |pmid= 9079663 |doi}}
*{{cite journal  | author=Ting NS |title=DNA-dependent protein kinase interacts with antigen receptor response element binding proteins NF90 and NF45 |journal=J. Biol. Chem. |volume=273 |issue= 4 |pages= 2136–2145 |year= 1998 |pmid= 9442054 |doi=10.1074/jbc.273.4.2136  |name-list-format=vanc| author2=Kao PN  | author3=Chan DW  | display-authors=3  | last4=Lintott  | first4=LG  | last5=Lees-Miller  | first5=SP  }}
*{{cite journal | author=Ting NS, Kao PN, Chan DW, ''et al.'' |title=DNA-dependent protein kinase interacts with antigen receptor response element binding proteins NF90 and NF45. |journal=J. Biol. Chem. |volume=273 |issue= 4 |pages= 2136-45 |year= 1998 |pmid= 9442054 |doi=  }}
*{{cite journal  | vauthors=Kimball SR, Heinzinger NK, Horetsky RL, Jefferson LS |title=Identification of interprotein interactions between the subunits of eukaryotic initiation factors eIF2 and eIF2B |journal=J. Biol. Chem. |volume=273 |issue= 5 |pages= 3039–3044 |year= 1998 |pmid= 9446619 |doi=10.1074/jbc.273.5.3039  }}
*{{cite journal  | author=Kimball SR, Heinzinger NK, Horetsky RL, Jefferson LS |title=Identification of interprotein interactions between the subunits of eukaryotic initiation factors eIF2 and eIF2B. |journal=J. Biol. Chem. |volume=273 |issue= 5 |pages= 3039-44 |year= 1998 |pmid= 9446619 |doi}}
*{{cite journal  | author=Shi Y |title=Identification and characterization of pancreatic eukaryotic initiation factor 2 alpha-subunit kinase, PEK, involved in translational control |journal=Mol. Cell. Biol. |volume=18 |issue= 12 |pages= 7499–509 |year= 1998 |pmid= 9819435 |doi=  10.1128/MCB.18.12.7499| pmc=109330  |name-list-format=vanc| author2=Vattem KM  | author3=Sood R  | display-authors=3  | last4=An  | first4=J  | last5=Liang  | first5=J  | last6=Stramm  | first6=L  | last7=Wek  | first7=RC  }}
*{{cite journal | author=Shi Y, Vattem KM, Sood R, ''et al.'' |title=Identification and characterization of pancreatic eukaryotic initiation factor 2 alpha-subunit kinase, PEK, involved in translational control. |journal=Mol. Cell. Biol. |volume=18 |issue= 12 |pages= 7499-509 |year= 1998 |pmid= 9819435 |doi=  }}
*{{cite journal  | vauthors=Satoh S, Hijikata M, Handa H, Shimotohno K |title=Caspase-mediated cleavage of eukaryotic translation initiation factor subunit 2alpha |journal=Biochem. J. |volume=342 |issue=  1|pages= 65–70 |year= 1999 |pmid= 10432301 |doi=10.1042/0264-6021:3420065  | pmc=1220437  }}
*{{cite journal  | author=Satoh S, Hijikata M, Handa H, Shimotohno K |title=Caspase-mediated cleavage of eukaryotic translation initiation factor subunit 2alpha. |journal=Biochem. J. |volume=342 ( Pt 1) |issue= |pages= 65-70 |year= 1999 |pmid= 10432301 |doi=  }}
*{{cite journal  | vauthors=Berlanga JJ, Santoyo J, De Haro C |title=Characterization of a mammalian homolog of the GCN2 eukaryotic initiation factor 2alpha kinase |journal=Eur. J. Biochem. |volume=265 |issue= 2 |pages= 754–762 |year= 1999 |pmid= 10504407 |doi=10.1046/j.1432-1327.1999.00780.x  }}
*{{cite journal  | author=Berlanga JJ, Santoyo J, De Haro C |title=Characterization of a mammalian homolog of the GCN2 eukaryotic initiation factor 2alpha kinase. |journal=Eur. J. Biochem. |volume=265 |issue= 2 |pages= 754-62 |year= 1999 |pmid= 10504407 |doi=  }}
*{{cite journal  | author=Lu J |title=The interferon-induced double-stranded RNA-activated protein kinase PKR will phosphorylate serine, threonine, or tyrosine at residue 51 in eukaryotic initiation factor 2alpha |journal=J. Biol. Chem. |volume=274 |issue= 45 |pages= 32198–32203 |year= 1999 |pmid= 10542257 |doi=10.1074/jbc.274.45.32198  |name-list-format=vanc| author2=O'Hara EB  | author3=Trieselmann BA  | display-authors=3  | last4=Romano  | first4=PR  | last5=Dever  | first5=TE }}
*{{cite journal  | author=Lu J, O'Hara EB, Trieselmann BA, ''et al.'' |title=The interferon-induced double-stranded RNA-activated protein kinase PKR will phosphorylate serine, threonine, or tyrosine at residue 51 in eukaryotic initiation factor 2alpha. |journal=J. Biol. Chem. |volume=274 |issue= 45 |pages= 32198-203 |year= 1999 |pmid= 10542257 |doi=  }}
}}
}}
{{refend}}
{{refend}}
{{PDB Gallery|geneid=1965}}
{{Initiation factors}}


{{protein-stub}}
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Latest revision as of 00:24, 31 August 2017

VALUE_ERROR (nil)
Identifiers
Aliases
External IDsGeneCards: [1]
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

n/a

n/a

RefSeq (protein)

n/a

n/a

Location (UCSC)n/an/a
PubMed searchn/an/a
Wikidata
View/Edit Human

Eukaryotic translation initiation factor 2 subunit 1 (eIF2α) is a protein that in humans is encoded by the EIF2S1 gene.[1][2]

Function

The protein encoded by this gene is the alpha (α) subunit of the translation initiation factor eIF2 complex which catalyzes an early regulated step of protein synthesis initiation, promoting the binding of the initiator tRNA (Met-tRNAiMet) to 40S ribosomal subunits. Binding occurs as a ternary complex of methionyl-tRNA, eIF2, and GTP. eIF2 is composed of 3 nonidentical subunits, alpha (α, 36 kD, this article), beta (β, 38 kD), and gamma (γ, 52 kD). The rate of formation of the ternary complex is modulated by the phosphorylation state of eIF2α.[2]

Clinical significance

After reperfusion following brain ischemia, there is inhibition of neuron protein synthesis due to phosphorylation of eIF2α. There is colocalization between phosphorylated eIF2α and cytosolic cytochrome c, which is released from mitochondria in apoptosis. Phosphorylated Eif2-alpha appeared before cytochrome c release, suggesting that phosphorylation of eIF2α triggers cytochrome c release during apoptotic cell death.[3]

Mice heterozygous for the S51A mutation become obese and diabetic on a high-fat diet. Glucose intolerance resulted from reduced insulin secretion, defective transport of proinsulin, and a reduced number of insulin granules in beta cells. Hence proper functioning of eIF2α appears essential for preventing diet-induced type II diabetes.[4]

Dephosphorylation inhibitors

Salubrinal is a selective inhibitor of enzymes that dephosphorylate eIF2α.[5] Salubrinal also blocks eIF2α dephosphorylation by a herpes simplex virus protein and inhibits viral replication. eIF2α phosphorylation is cytoprotective during endoplasmic reticulum stress.[6][7]

See also

References

  1. Ernst H, Duncan RF, Hershey JW (Mar 1987). "Cloning and sequencing of complementary DNAs encoding the alpha-subunit of translational initiation factor eIF-2. Characterization of the protein and its messenger RNA". J Biol Chem. 262 (3): 1206–12. PMID 2948954.
  2. 2.0 2.1 "Entrez Gene: EIF2S1 eukaryotic translation initiation factor 2, subunit 1 alpha, 35kDa". National Center for Biotechnology Information, U.S. National Library of Medicine. Retrieved 2010-10-05.
  3. Page AB, Owen CR, Kumar R, Miller JM, Rafols JA, White BC, DeGracia DJ, Krause GS (July 2003). "Persistent eIF2alpha(P) is colocalized with cytoplasmic cytochrome c in vulnerable hippocampal neurons after 4 hours of reperfusion following 10-minute complete brain ischemia". Acta Neuropathol. 106 (1): 8–16. doi:10.1007/s00401-003-0693-2. PMID 12687390.
  4. Scheuner D, Vander Mierde D, Song B, Flamez D, Creemers JW, Tsukamoto K, Ribick M, Schuit FC, Kaufman RJ (July 2005). "Control of mRNA translation preserves endoplasmic reticulum function in beta cells and maintains glucose homeostasis". Nat. Med. 11 (7): 757–764. doi:10.1038/nm1259. PMID 15980866.
  5. Boyce M, Bryant KF, Jousse C, Long K, Harding HP, Scheuner D, Kaufman RJ, Ma D, Coen DM, Ron D, Yuan J (February 2005). "A selective inhibitor of eIF2alpha dephosphorylation protects cells from ER stress". Science. 307 (5711): 935–939. doi:10.1126/science.1101902. PMID 15705855.
  6. Harding HP, Zhang Y, Bertolotti A, Zeng H, Ron D (May 2000). "Perk is essential for translational regulation and cell survival during the unfolded protein response". Mol. Cell. 5 (5): 897–904. doi:10.1016/S1097-2765(00)80330-5. PMID 10882126.
  7. Scheuner D, Song B, McEwen E, Liu C, Laybutt R, Gillespie P, Saunders T, Bonner-Weir S, Kaufman RJ (June 2001). "Translational control is required for the unfolded protein response and in vivo glucose homeostasis". Mol. Cell. 7 (6): 1165–1176. doi:10.1016/S1097-2765(01)00265-9. PMID 11430820.

Further reading