Reviewed, UniProtKB/Swiss-Prot Q9R1T7 (ICOS_RAT)

Names and origin

Protein names

Recommended name:
    Inducible T-cell costimulator
Alternative name(s):
    Activation-inducible lymphocyte immunomediatory molecule
    CD_antigen=CD278

Gene names

Name:	Icos
Synonyms:	Ailim

Organism

Rattus norvegicus (Rat)

Taxonomic identifier

10116 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Glires › Rodentia › Sciurognathi › Muroidea › Muridae › Murinae › Rattus

Protein attributes

Sequence length	200 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Enhances all basic T-cell responses to a foreign antigen, namely proliferation, secretion of lymphokines, up-regulation of molecules that mediate cell-cell interaction, and effective help for antibody secretion by B-cells. Essential both for efficient interaction between T and B-cells and for normal antibody responses to T-cell dependent antigens. Does not up-regulate the production of interleukin-2, but superinduces the synthesis of interleukin-10. Prevents the apoptosis of pre-activated T-cells. Plays a critical role in CD40-mediated class switching of immunoglobin isotypes By similarity. Ref.1
Subunit structure	Homodimer; disulfide-linked. Ref.1
Subcellular location	Membrane; Single-pass type I membrane protein Potential.
Tissue specificity	Strongly expressed in the spleen and lung. Lower expression seen in liver, kidney and testis. Ref.1
Induction	Expression on T-cells is drastically induced by phorbol myristate acetate (PMA) and Ca-ionophore or the engagement of CD3 and CD28. Ref.1
Post-translational modification	N-glycosylated By similarity.
Sequence similarities	Contains 1 Ig-like V-type (immunoglobulin-like) domain.

Ontologies

Keywords
Cellular component	Membrane
Coding sequence diversity	Alternative splicing
Domain	Immunoglobulin domain Signal Transmembrane
PTM	Disulfide bond Glycoprotein
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological process	T cell costimulation Ref.1 Inferred from direct assay. Source: RGD T cell tolerance induction Inferred from mutant phenotype. Source: RGD cell-cell adhesion Inferred from direct assay. Source: RGD
Cellular component	integral to plasma membrane Ref.1 Non-traceable author statement. Source: RGD
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]

Isoform 1 (identifier: Q9R1T7-1)

Also known as: AILIM-1;

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Isoform 2 (identifier: Q9R1T7-2)

Also known as: AILIM-2;

The sequence of this isoform differs from the canonical sequence as follows:
     198-200: MTS → TAPLRALGRGEHSSCQDRN

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Signal peptide	1 – 20	20	Ref.1
	Chain	21 – 200	180	Inducible T-cell costimulator		PRO_0000014808
Regions
	Topological domain	21 – 145	125	Extracellular Potential
	Transmembrane	146 – 166	21	Potential
	Topological domain	167 – 200	34	Cytoplasmic Potential
	Domain	30 – 133	104	Ig-like V-type
Amino acid modifications
	Glycosylation	89	1	N-linked (GlcNAc...) Potential
	Glycosylation	123	1	N-linked (GlcNAc...) Potential
	Disulfide bond	42 ↔ 109		By similarity
	Disulfide bond	63 ↔ 83		By similarity
Natural variations
	Alternative sequence	198 – 200	3	MTS → TAPLRALGRGEHSSCQDRN in isoform 2.		VSP_010789

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 (AILIM-1) [UniParc]. Last modified May 1, 2000. Version 1. Checksum: 0A74C35581F129D4	FASTA	200	22,529
	10 20 30 40 50 60 MKPYFSCVFV FCFLIKLLTG ELNDLANHRM FSFHDGGVQI SCNYPETVQQ LKMQLFKDRE 70 80 90 100 110 120 VLCDLTKTKG SGNTVSIKNP MSCPYQLSNN SVSFFLDNAD SSQGSYFLCS LSIFDPPPFQ 130 140 150 160 170 180 EKNLSGGYLL IYESQLCCQL KLWLPVGCAA FVAALLFGCI FIVWFAKKKY RSSVHDPNSE 190 200 YMFMAAVNTN KKSRLAGMTS
	Isoform 2 (AILIM-2). Checksum: 772E01320982B15A	FASTA	216	24,260
	10 20 30 40 50 60 MKPYFSCVFV FCFLIKLLTG ELNDLANHRM FSFHDGGVQI SCNYPETVQQ LKMQLFKDRE 70 80 90 100 110 120 VLCDLTKTKG SGNTVSIKNP MSCPYQLSNN SVSFFLDNAD SSQGSYFLCS LSIFDPPPFQ 130 140 150 160 170 180 EKNLSGGYLL IYESQLCCQL KLWLPVGCAA FVAALLFGCI FIVWFAKKKY RSSVHDPNSE 190 200 210 YMFMAAVNTN KKSRLAGTAP LRALGRGEHS SCQDRN

References

[1]

"Identification and characterization of rat AILIM/ICOS, a novel T-cell costimulatory molecule, related to the CD28/CTLA4 family." Tezuka K., Tsuji T., Hirano D., Tamatani T., Sakamaki K., Kobayashi Y., Kamada M. Biochem. Biophys. Res. Commun. 276:335-345(2000) [PubMed: 11006126] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORMS 1 AND 2), PROTEIN SEQUENCE OF 21-40, FUNCTION, SUBUNIT, INDUCTION, TISSUE SPECIFICITY. Tissue: Spleen.

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Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AB023133 mRNA. Translation: BAA82127.1. AB023134 mRNA. Translation: BAA82128.1.
IPI	IPI00207669. IPI00454381.
PIR	JC7396. JC7397.
RefSeq	NP_072132.1.
UniGene	Rn.168816
3D structure databases
SMR	Q9R1T7. Positions 29-131.
ModBase	Search...
Genome annotation databases
GeneID	64545.
KEGG	rno:64545.
Organism-specific databases
CTD	64545.
RGD	620123. Icos.
Phylogenomic databases
HOVERGEN	Q9R1T7.
Gene expression databases
Genevestigator	Q9R1T7.
Family and domain databases
PROSITE	PS50835. IG_LIKE. False negative. [Graphical view]
ProtoNet	Search...
Other Resources
NextBio	613416.

Entry information

Entry name

ICOS_RAT

Accession

Primary (citable) accession number: Q9R1T7
Secondary accession number(s): Q9WVR9

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 19, 2004
Last sequence update:	May 1, 2000
Last modified:	January 19, 2010
This is version 38 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HPI (Human Proteome Initiative)