View source for EIF2B

{{Short description|Multisubunit guanine nucleotide exchange factor}}
{{lowercase}}
'''eIF2B''' is a [[protein complex]] found in [[eukaryote]]s. It is the [[guanine nucleotide exchange factor]] for the [[eIF-2|eukaryotic initiation factor 2]] and therefore converts the inactive eIF2-[[guanosine diphosphate|GDP]] to the active eIF2-[[guanosine triphosphate|GTP]]. This activation is hindered by [[phosphorylation]] of the alpha subunit of eIF2, which leads to a stable eIF2α-P-GDP-eIF2B complex and therefore inhibits [[Eukaryotic translation|translation]] initiation.<ref name="test">{{cite journal | pmid = 16246152 | doi=10.1042/BST20051487 | volume=33 | issue=Pt 6 | title=eIF2B, a mediator of general and gene-specific translational control. | date=Dec 2005 | journal=Biochem Soc Trans | pages=1487–92| last1=Pavitt | first1=G.D. }}</ref>

Human genes which encode eIF-2B proteins include:
* [[EIF2B1]] – alpha subunit (26kDa)
* [[EIF2B2]] – beta subunit (39kDa)
* [[EIF2B3]] – gamma subunit (58kDa)
* [[EIF2B4]] – delta subunit (67kDa)
* [[EIF2B5]] – epsilon subunit (82kDa)

==References==
{{reflist|30em}}

{{GTP-binding protein regulators}}

[[Category:Protein biosynthesis]]
[[Category:Gene expression]]
[[Category:Proteins]]


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