P83268 (IF2A_RABIT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Eukaryotic translation initiation factor 2 subunit 1

Alternative name(s):
Eukaryotic translation initiation factor 2 subunit alpha
Short name=eIF-2-alpha
Short name=eIF-2A
Short name=eIF-2alpha

Gene names

Name:	EIF2S1
Synonyms:	EIF2A

Organism

Oryctolagus cuniculus (Rabbit) [Reference proteome]

Taxonomic identifier

9986 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Euarchontoglires › Glires › Lagomorpha › Leporidae › Oryctolagus

Protein attributes

Sequence length	52 AA.
Sequence status	Fragment.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Functions in the early steps of protein synthesis by forming a ternary complex with GTP and initiator tRNA. This complex binds to a 40S ribosomal subunit, followed by mRNA binding to form a 43S preinitiation complex. Junction of the 60S ribosomal subunit to form the 80S initiation complex is preceded by hydrolysis of the GTP bound to eIF-2 and release of an eIF-2-GDP binary complex. In order for eIF-2 to recycle and catalyze another round of initiation, the GDP bound to eIF-2 must exchange with GTP by way of a reaction catalyzed by eIF-2B.
Subunit structure	Heterotrimer composed of an alpha, a beta and a gamma chain. Component of an EIF2 complex at least composed of CELF1/CUGBP1, CALR, CALR3, EIF2S1, EIF2S2, HSP90B1 and HSPA5. Interacts with ABCF1. Associates with ribosomes. Interaction with METAP2 protects EIF2S1 from inhibitory phosphorylation By similarity.
Subcellular location	Cytoplasmic granule By similarity. Note: The cytoplasmic granules are stress granules which are a dense aggregation in the cytosol composed of proteins and RNAs that appear when the cell is under stress. Co-localizes with NANOS3 in the stress granules By similarity.
Post-translational modification	Substrate for at least 4 kinases: EIF2AK3/PERK, GCN2, HRI and PKR. Phosphorylation stabilizes the eIF-2/GDP/eIF-2B complex and prevents GDP/GTP exchange reaction, thus impairing the recycling of eIF-2 between successive rounds of initiation and leading to global inhibition of translation By similarity.
Sequence similarities	Belongs to the eIF-2-alpha family. Contains 1 S1 motif domain.

Ontologies

Keywords
Biological process	Protein biosynthesis Translation regulation
Ligand	RNA-binding
Molecular function	Initiation factor
PTM	Phosphoprotein
Technical term	Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological_process	regulation of translation Inferred from electronic annotation. Source: UniProtKB-KW
Cellular_component	cytoplasmic stress granule Inferred from sequence or structural similarity. Source: UniProtKB
Molecular_function	GTP binding Non-traceable author statement Ref.2Ref.1. Source: UniProtKB ribosome binding Inferred from sequence or structural similarity. Source: UniProtKB translation initiation factor activity Non-traceable author statement Ref.2Ref.1. Source: UniProtKB
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – ›52	›52	Eukaryotic translation initiation factor 2 subunit 1		PRO_0000137385
Regions
	Domain	16 – ›52	›37	S1 motif
Amino acid modifications
	Modified residue	48	1	Phosphoserine; by HRI Ref.1
	Modified residue	51	1	Phosphoserine; by EIF2AK3, GCN2, HRI and PKR By similarity
Experimental info
	Sequence uncertainty	10	1
	Sequence uncertainty	44	1
	Sequence uncertainty	52	1
	Sequence conflict	10	1	H → R AA sequence Ref.2
	Sequence conflict	16	1	E → Q AA sequence Ref.1
	Non-terminal residue	52	1

Sequences

	Sequence		Length	Mass (Da)
	P83268 [UniParc]. Last modified March 1, 2002. Version 1. Checksum: 52E63D8DCEA6B804	FASTA	52	5,974
	10 20 30 40 50 PGLSCRFYQH KFPEVEDVVM VNVRSIAEMG AYVSLLEYNN IEGRILLSEL SR

References

[1]	"The NH2-terminal sequence of the alpha and gamma subunits of eukaryotic initiation factor 2 and the phosphorylation site for the heme-regulated eIF-2 alpha kinase." Wettenhall R.E.H., Kudlicki W., Kramer G., Hardesty B. J. Biol. Chem. 261:12444-12447(1986) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE, PHOSPHORYLATION AT SER-48. Tissue: Reticulocyte.
[2]	"The purification and characterization of subunits alpha, beta, and gamma from the rabbit reticulocyte eukaryotic initiation factor 2." Schafer M.P., Fairwell T., Parker D.S., Knight M., Anderson W.F., Safer B. Arch. Biochem. Biophys. 255:337-346(1987) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-23. Tissue: Reticulocyte.

Cross-references

3D structure databases
ProteinModelPortal	P83268.
SMR	P83268. Positions 3-50.
ModBase	Search...
Protein-protein interaction databases
IntAct	P83268. 1 interaction.
STRING	9986.ENSOCUP00000010342.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Phylogenomic databases
eggNOG	COG1093.
HOGENOM	HOG000199476.
OrthoDB	EOG4BZN35.
Family and domain databases
Gene3D	2.40.50.140. 1 hit.
InterPro	IPR012340. NA-bd_OB-fold. IPR003029. Rbsml_prot_S1_RNA-bd_dom. [Graphical view]
Pfam	PF00575. S1. 1 hit. [Graphical view]
SUPFAM	SSF50249. Nucleic_acid_OB. 1 hit.
PROSITE	PS50126. S1. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

IF2A_RABIT

Accession

Primary (citable) accession number: P83268

Entry history

Integrated into UniProtKB/Swiss-Prot:	May 27, 2002
Last sequence update:	March 1, 2002
Last modified:	April 3, 2013
This is version 65 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program