ID   IL2_AILME               Reviewed;         155 AA.
AC   Q5PXD0; Q0MS74;
DT   12-APR-2005, integrated into UniProtKB/Swiss-Prot.
DT   04-JAN-2005, sequence version 1.
DT   03-AUG-2022, entry version 87.
DE   RecName: Full=Interleukin-2;
DE            Short=IL-2;
DE   AltName: Full=T-cell growth factor;
DE            Short=TCGF;
DE   Flags: Precursor;
GN   Name=IL2;
OS   Ailuropoda melanoleuca (Giant panda).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Carnivora; Caniformia; Ursidae; Ailuropoda.
OX   NCBI_TaxID=9646;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RA   Xu L., Zou F., Yue B., Lai B., Zhang Z.;
RT   "Molecular cloning and expression of interleukin 2 from giant panda.";
RL   Submitted (NOV-2004) to the EMBL/GenBank/DDBJ databases.
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RA   Huang D., Yang G., Zhang Z., Zhang A., Guo W., Wang C., Hou R., Shen F.;
RT   "Cloning and sequence analysis of IL-2 gene in Ailuropoda melanoleuca.";
RL   Submitted (JUL-2006) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Cytokine produced by activated CD4-positive helper T-cells
CC       and to a lesser extend activated CD8-positive T-cells and natural
CC       killer (NK) cells that plays pivotal roles in the immune response and
CC       tolerance. Binds to a receptor complex composed of either the high-
CC       affinity trimeric IL-2R (IL2RA/CD25, IL2RB/CD122 and IL2RG/CD132) or
CC       the low-affinity dimeric IL-2R (IL2RB and IL2RG). Interaction with the
CC       receptor leads to oligomerization and conformation changes in the IL-2R
CC       subunits resulting in downstream signaling starting with
CC       phosphorylation of JAK1 and JAK3. In turn, JAK1 and JAK3 phosphorylate
CC       the receptor to form a docking site leading to the phosphorylation of
CC       several substrates including STAT5. This process leads to activation of
CC       several pathways including STAT, phosphoinositide-3-kinase/PI3K and
CC       mitogen-activated protein kinase/MAPK pathways. Functions as a T-cell
CC       growth factor and can increase NK-cell cytolytic activity as well.
CC       Promotes strong proliferation of activated B-cells and subsequently
CC       immunoglobulin production. Plays a pivotal role in regulating the
CC       adaptive immune system by controlling the survival and proliferation of
CC       regulatory T-cells, which are required for the maintenance of immune
CC       tolerance. Moreover, participates in the differentiation and
CC       homeostasis of effector T-cell subsets, including Th1, Th2, Th17 as
CC       well as memory CD8-positive T-cells. {ECO:0000250|UniProtKB:P60568}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the IL-2 family. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; AY823739; AAV73802.1; -; mRNA.
DR   EMBL; DQ852339; ABH10824.1; -; mRNA.
DR   RefSeq; XP_011228862.1; XM_011230560.2.
DR   AlphaFoldDB; Q5PXD0; -.
DR   SMR; Q5PXD0; -.
DR   STRING; 9646.ENSAMEP00000006235; -.
DR   Ensembl; ENSAMET00000006489; ENSAMEP00000006235; ENSAMEG00000005901.
DR   GeneID; 100480862; -.
DR   CTD; 3558; -.
DR   eggNOG; ENOG502RVR5; Eukaryota.
DR   GeneTree; ENSGT00390000003555; -.
DR   HOGENOM; CLU_124210_0_0_1; -.
DR   InParanoid; Q5PXD0; -.
DR   OMA; NGVNNYE; -.
DR   OrthoDB; 1491449at2759; -.
DR   TreeFam; TF338200; -.
DR   Proteomes; UP000008912; Unassembled WGS sequence.
DR   GO; GO:0005615; C:extracellular space; IEA:UniProtKB-KW.
DR   GO; GO:0005125; F:cytokine activity; IEA:UniProtKB-KW.
DR   GO; GO:0008083; F:growth factor activity; IEA:UniProtKB-KW.
DR   GO; GO:0005134; F:interleukin-2 receptor binding; IEA:Ensembl.
DR   GO; GO:0050798; P:activated T cell proliferation; IEA:Ensembl.
DR   GO; GO:0002250; P:adaptive immune response; IEA:UniProtKB-KW.
DR   GO; GO:0097192; P:extrinsic apoptotic signaling pathway in absence of ligand; IEA:Ensembl.
DR   GO; GO:0002366; P:leukocyte activation involved in immune response; IEA:Ensembl.
DR   GO; GO:0002903; P:negative regulation of B cell apoptotic process; IEA:Ensembl.
DR   GO; GO:0050728; P:negative regulation of inflammatory response; IEA:Ensembl.
DR   GO; GO:0050672; P:negative regulation of lymphocyte proliferation; IEA:Ensembl.
DR   GO; GO:2000320; P:negative regulation of T-helper 17 cell differentiation; IEA:Ensembl.
DR   GO; GO:0042104; P:positive regulation of activated T cell proliferation; IEA:Ensembl.
DR   GO; GO:0030890; P:positive regulation of B cell proliferation; IEA:Ensembl.
DR   GO; GO:0032729; P:positive regulation of interferon-gamma production; IEA:Ensembl.
DR   GO; GO:0032740; P:positive regulation of interleukin-17 production; IEA:Ensembl.
DR   GO; GO:0048304; P:positive regulation of isotype switching to IgG isotypes; IEA:Ensembl.
DR   GO; GO:1900100; P:positive regulation of plasma cell differentiation; IEA:Ensembl.
DR   GO; GO:0045944; P:positive regulation of transcription by RNA polymerase II; IEA:Ensembl.
DR   GO; GO:0042531; P:positive regulation of tyrosine phosphorylation of STAT protein; IEA:Ensembl.
DR   GO; GO:2000561; P:regulation of CD4-positive, alpha-beta T cell proliferation; IEA:Ensembl.
DR   GO; GO:0046013; P:regulation of T cell homeostatic proliferation; IEA:Ensembl.
DR   GO; GO:0006366; P:transcription by RNA polymerase II; IEA:Ensembl.
DR   GO; GO:0007260; P:tyrosine phosphorylation of STAT protein; IEA:Ensembl.
DR   Gene3D; 1.20.1250.10; -; 1.
DR   InterPro; IPR009079; 4_helix_cytokine-like_core.
DR   InterPro; IPR000779; IL-2.
DR   InterPro; IPR030477; IL-2_CS.
DR   Pfam; PF00715; IL2; 1.
DR   PRINTS; PR00265; INTERLEUKIN2.
DR   SMART; SM00189; IL2; 1.
DR   SUPFAM; SSF47266; SSF47266; 1.
DR   PROSITE; PS00424; INTERLEUKIN_2; 1.
PE   2: Evidence at transcript level;
KW   Adaptive immunity; Cytokine; Disulfide bond; Glycoprotein; Growth factor;
KW   Immunity; Reference proteome; Secreted; Signal.
FT   SIGNAL          1..20
FT                   /evidence="ECO:0000250"
FT   CHAIN           21..155
FT                   /note="Interleukin-2"
FT                   /id="PRO_0000015469"
FT   CARBOHYD        23
FT                   /note="O-linked (GalNAc...) threonine"
FT                   /evidence="ECO:0000250"
FT   DISULFID        79..127
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   155 AA;  17934 MW;  CB2C8BC0842DDF0F CRC64;
     MYKMQLLYCI ALTLVLVANS APTPSSPTKE TQQQLEQLML DLRLLLNGVN NYENPKLSRM
     LTFKFYMPKK ATELKHLQCL AEELKLLEEV LYLDQSKNLH LTDIKELMSN INVTLLKLKG
     SEASFKCEYD DETVTITEFL NKWITFCQSI FSTLT