Reviewed, UniProtKB/Swiss-Prot P14741 (EI2BA_YEAST)

Names and origin

Protein names

Recommended name:
    Translation initiation factor eIF-2B subunit alpha
Alternative name(s):
    eIF-2B GDP-GTP exchange factor subunit alpha
    Guanine nucleotide exchange factor subunit GCN3
    GCD complex subunit GCN3
    Transcriptional activator GCN3

Gene names

Name:	GCN3
Synonyms:	AAS2, TIF221
Ordered Locus Names:	YKR026C

Organism

Saccharomyces cerevisiae (Baker's yeast) [Complete proteome]

Taxonomic identifier

4932 [NCBI]

Taxonomic lineage

Eukaryota › Fungi › Dikarya › Ascomycota › Saccharomycotina › Saccharomycetes › Saccharomycetales › Saccharomycetaceae › Saccharomyces

Protein attributes

Sequence length	305 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Acts as a non-essential regulatory component of the translation initiation factor 2B (eIF2-B or GCD complex), which catalyzes the exchange of eukaryotic initiation factor 2 (eIF-2)-bound GDP for GTP and is regulated by phosphorylated eIF-2. It activates the synthesis of GCN4 in yeast under amino acid starvation conditions by suppressing the inhibitory effects of multiple AUG codons present in the leader of GCN4 mRNA. It may promote either repression or activation of GCN4 expression depending on amino acid availability. Modulation of GCN3 regulatory function in response to amino acid availability occurs post-translationally. Ref.3 Ref.4
Subunit structure	Translation initiation factor 2B (eIF2-B) is composed of five different subunits; alpha (GCN3), beta (GCD7), gamma (GCD1), delta (GCD2) and epsilon (GCD6). A regulatory subcomplex comprising GCN3, GCD7 and GCD2 interacts preferentially with phosphorylated eIF-2 and has no exchange activity in vitro.
Miscellaneous	Present with 8970 molecules/cell in log phase SD medium. Ref.5
Sequence similarities	Belongs to the EIF-2B alpha/beta/delta subunits family.

Ontologies

Keywords
Biological process	Protein biosynthesis Translation regulation
Molecular function	Activator Initiation factor Repressor
PTM	Phosphoprotein
Technical term	Complete proteome
Gene Ontology (GO)
Biological process	regulation of translational initiation Ref.3 Inferred from direct assay. Source: SGD translation Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	eukaryotic translation initiation factor 2B complex Ref.3 Inferred from direct assay. Source: SGD guanyl-nucleotide exchange factor complex Ref.3 Inferred from direct assay. Source: SGD
Molecular function	enzyme regulator activity Inferred from mutant phenotype. Source: SGD identical protein binding Inferred from physical interaction. Source: IntAct translation initiation factor activity Inferred from direct assay. Source: SGD
Complete GO annotation...

Binary interactions

With	Entry	#Exp.	IntAct	Notes
itself		1	EBI-6253,EBI-6253
BIT2	P38346	1	EBI-6253,EBI-21144
GCD2	P12754	1	EBI-6253,EBI-6265
GCD7	P32502	2	EBI-6253,EBI-6260

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 305	305	Translation initiation factor eIF-2B subunit alpha		PRO_0000156060
Amino acid modifications
	Modified residue	291	1	Phosphothreonine Ref.6

Sequences

	Sequence		Length	Mass (Da)
	P14741-1 [UniParc]. Last modified April 1, 1990. Version 1. Checksum: 8E9A928D6D56E12B	FASTA	305	34,025
	10 20 30 40 50 60 MSEFNITETY LRFLEEDTEM TMPIAAIEAL VTLLRIKTPE TAAEMINTIK SSTEELIKSI 70 80 90 100 110 120 PNSVSLRAGC DIFMRFVLRN LHLYGDWENC KQHLIENGQL FVSRAKKSRN KIAEIGVDFI 130 140 150 160 170 180 ADDDIILVHG YSRAVFSLLN HAANKFIRFR CVVTESRPSK QGNQLYTLLE QKGIPVTLIV 190 200 210 220 230 240 DSAVGAVIDK VDKVFVGAEG VAESGGIINL VGTYSVGVLA HNARKPFYVV TESHKFVRMF 250 260 270 280 290 300 PLSSDDLPMA GPPLDFTRRT DDLEDALRGP TIDYTAQEYI TALITDLGVL TPSAVSEELI KMWYD

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Molecular analysis of GCN3, a translational activator of GCN4: evidence for posttranslational control of GCN3 regulatory function." Hannig E.M., Hinnebusch A.G. Mol. Cell. Biol. 8:4808-4820(1988) [PubMed: 3062370] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	"Complete DNA sequence of yeast chromosome XI." Dujon B., Alexandraki D., Andre B., Ansorge W., Baladron V., Ballesta J.P.G., Banrevi A., Bolle P.-A., Bolotin-Fukuhara M., Bossier P., Bou G., Boyer J., Buitrago M.J., Cheret G., Colleaux L., Daignan-Fornier B., del Rey F., Dion C. , Domdey H., Duesterhoeft A., Duesterhus S., Entian K.-D., Erfle H., Esteban P.F., Feldmann H., Fernandes L., Fobo G.M., Fritz C., Fukuhara H., Gabel C., Gaillon L., Garcia-Cantalejo J.M., Garcia-Ramirez J.J., Gent M.E., Ghazvini M., Goffeau A., Gonzalez A., Grothues D., Guerreiro P., Hegemann J.H., Hewitt N., Hilger F., Hollenberg C.P., Horaitis O., Indge K.J., Jacquier A., James C.M., Jauniaux J.-C., Jimenez A., Keuchel H., Kirchrath L., Kleine K., Koetter P., Legrain P., Liebl S., Louis E.J., Maia e Silva A., Marck C., Monnier A.-L., Moestl D., Mueller S., Obermaier B., Oliver S.G., Pallier C., Pascolo S., Pfeiffer F., Philippsen P., Planta R.J., Pohl F.M., Pohl T.M., Poehlmann R., Portetelle D., Purnelle B., Puzos V., Ramezani Rad M., Rasmussen S.W., Remacha M.A., Revuelta J.L., Richard G.-F., Rieger M., Rodrigues-Pousada C., Rose M., Rupp T., Santos M.A., Schwager C., Sensen C., Skala J., Soares H., Sor F., Stegemann J., Tettelin H., Thierry A., Tzermia M., Urrestarazu L.A., van Dyck L., van Vliet-Reedijk J.C., Valens M., Vandenbol M., Vilela C., Vissers S., von Wettstein D., Voss H., Wiemann S., Xu G., Zimmermann J., Haasemann M., Becker I., Mewes H.-W. Nature 369:371-378(1994) [PubMed: 8196765] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: ATCC 96604 / S288c / FY1679.
[3]	"A protein complex of translational regulators of GCN4 mRNA is the guanine nucleotide-exchange factor for translation initiation factor 2 in yeast." Cigan A.M., Bushman J.L., Boal T.R., Hinnebusch A.G. Proc. Natl. Acad. Sci. U.S.A. 90:5350-5354(1993) [PubMed: 8506384] [Abstract] Cited for: IDENTIFICATION IN THE EIF2-B COMPLEX, FUNCTION OF THE EIF2-B COMPLEX.
[4]	"eIF2 independently binds two distinct eIF2B subcomplexes that catalyze and regulate guanine-nucleotide exchange." Pavitt G.D., Ramaiah K.V., Kimball S.R., Hinnebusch A.G. Genes Dev. 12:514-526(1998) [PubMed: 9472020] [Abstract] Cited for: FUNCTION, IDENTIFICATION IN A EIF2-B SUBCOMPLEX.
[5]	"Global analysis of protein expression in yeast." Ghaemmaghami S., Huh W.-K., Bower K., Howson R.W., Belle A., Dephoure N., O'Shea E.K., Weissman J.S. Nature 425:737-741(2003) [PubMed: 14562106] [Abstract] Cited for: LEVEL OF PROTEIN EXPRESSION [LARGE SCALE ANALYSIS].
[6]	"A multidimensional chromatography technology for in-depth phosphoproteome analysis." Albuquerque C.P., Smolka M.B., Payne S.H., Bafna V., Eng J., Zhou H. Mol. Cell. Proteomics 7:1389-1396(2008) [PubMed: 18407956] [Abstract] Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT THR-291, MASS SPECTROMETRY.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	M23356 Genomic DNA. Translation: AAA34637.1. Z28251 Genomic DNA. Translation: CAA82098.1.
PIR	A31562.
RefSeq	NP_012951.1.
3D structure databases
SMR	P14741. Positions 24-301.
ModBase	Search...
Protein-protein interaction databases
DIP	DIP-1328N.
IntAct	P14741. 58 interactions.
STRING	P14741.
Proteomic databases
PeptideAtlas	P14741.
PRIDE	P14741.
Genome annotation databases
Ensembl	YKR026C; YKR026C; YKR026C; Saccharomyces cerevisiae. [Genome view]
GeneID	853896.
KEGG	sce:YKR026C.
NMPDR	fig|4932.3.peg.3937.
Organism-specific databases
CYGD	YKR026c.
SGD	S000001734. GCN3.
Phylogenomic databases
eggNOG	fuNOG05276.
HOGENOM	HBG315460.
OMA	SGQKMAK.
OrthoDB	EOG9TXD82.
PhylomeDB	P14741.
Gene expression databases
ArrayExpress	P14741.
Genevestigator	P14741.
GermOnline	YKR026C. Saccharomyces cerevisiae.
Family and domain databases
InterPro	IPR000649. IF-2B_related. [Graphical view]
PANTHER	PTHR10233. IF-2B_related. 1 hit.
Pfam	PF01008. IF-2B. 1 hit. [Graphical view]
ProtoNet	Search...
Other Resources
NextBio	975213.

Entry information

Entry name

EI2BA_YEAST

Accession

Primary (citable) accession number: P14741

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 1, 1990
Last sequence update:	April 1, 1990
Last modified:	January 19, 2010
This is version 82 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

FPAP (Fungal Proteome Annotation Project)