EIF2B

{{Short description|Multisubunit guanine nucleotide exchange factor}} {{lowercase}} '''eIF2B''' is a protein complex found in eukaryotes. It is the guanine nucleotide exchange factor for the eukaryotic initiation factor 2 and therefore converts the inactive eIF2-GDP to the active eIF2-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 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

{{enzyme-stub}}