ITGA11 (integrin, alpha 11)

2008-04-01   Svetlana N Popova , Donald Gullberg 

Department of Biomedicine, University of Bergen, Jonas Lies vei 91, NO-5009 Bergen, Norway

Identity

HGNC
LOCATION
15q23
LOCUSID
ALIAS
HsT18964
FUSION GENES

DNA/RNA

Description

The gene contains 30 exons and 29 introns; it is composed of a 30 nt long 5 untranslated region, a 3564-nucleotide open reading frame, a 329-nucleotide 3 noncoding sequence and a polyA tail.

Transcription

Gene analysis in silico reveals several potential splice variants, which still remain to be validated at the RNA level. The basal promoter is regulated by Sp1/ Sp3/ Ets-1 binding sites. How occupation of these cis-binding sites in the promoter results in a fibroblast-specific α11 expression pattern remains to be shown. One working hypothesis is that the combined binding of Sp1 with a specific member of the Ets family of transcription factors contributes to the tissue-specific expression pattern.

Proteins

Atlas Image
Scematic structure of the I-domain containing α11 integrin.
A. The integrins α subunit primary structure, including predicted divalent cation-binding sites (Mg2 as red star, and Ca2 as gray stars) is shown. The position of the inserted sequence of 22 amino acids in the Calf-1 domain is marked.
B. Schematic representations of straightened (active) conformations of the integrin. The arrangement of domains is based on the 3-dimensional crystal structure of the αvβ3-integrin, with an I domain added between the second and third β-propeller repeats.
I-d indicates I domain; PSI, plexin/semaphorin/integrin; and TM, -tail domain of integrin β subunit.

Description

The mature α11 peptide is 1166-amino acid-long (M.W. 145 kDa in SDS-PAGE under non-reducing conditions), which is longer than any other currently identified integrin α-chain (with the closest being αE, which is composed of 1160 amino acids). The extracellular domain contains seven FG-GAP repeats in the amino-terminal end with an inserted I domain between repeats 2 and 3. The I domain consists of 195 amino acids and includes a conserved metal ion-dependent adhesion site motif. In addition to the metal chelating site in the I domain, three potential divalent cation binding motifs with the consensus sequence DXD/NXDXXXD are present in repeats 5-7. A total of 20 cysteines are located in the extracellular domain. Of these, 16 are conserved in the most closely related integrin α10- and α1-chains, and they may contribute to intramolecular disulfide bonds. There is an inserted 22 amino acid sequence in the calf-1 domain in the stalk region at amino acids 804-826, distinguishing α11 from other integrin α-chains. The transmembrane region (amino acids 1142-1164) is 23 amino acids long and is followed by a cytoplasmic tail of 24 amino acids. The cytoplasmic tail contains the sequence GFFRS instead of the conserved GFFKR sequence found in all other alpha-chains except ITGA8 - alpha 10.

Expression

Analysis of α11 protein and mRNA expression and distribution in human and mouse embryos revealed a restricted expression on mesenchymal non-muscle cells in areas of highly organized interstitial collagen networks.

Localisation

Membrane-bound

Function

Integrin α11 subunit binds integrin beta 1 subunit to form a heterodimer and function as a receptor for interstitial collagens (with highest affinity for collagen type I). It is involved in cell attachment, cell migration and collagen reorganization on mesenchymal non-muscle cells.

Homology

When compared with other I domain-containing collagen-binding integrin subunits, α11 amino acid sequence shows the highest overall identity with integrin alpha 10 (42% identity) followed by integrin alpha 1 (37% identity), and integrin alpha 2 (35% identity). Of the non-I domain-containing integrins, integrin alpha 4 and integrin alpha 9 show the highest sequence similarity to α11. ITGA11 shows 86% identity with mouse integrin α11 at the nucleotide level, translating to 89% identity at the amino-acid level.

Implicated in

Entity name
Lung cancer
Disease
Lung cancer, the most common cause of cancer-related death in men and the second most common in women, is responsible for 1.3 million deaths worldwide annually. For treatment purposes, lung cancer is grouped into 2 major types: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). The latter group is a heterogeneous disease which can be classified histologically into many types, with the 4 major ones being adenocarcinomas, squamous cell carcinoma, large cell carcinoma and adenosquamous carcinoma. Adenocarcinoma accounts for about one third of lung cancers, with a majority arising in the peripheral lung tissue. In the Western world, most cases of adenocarcinoma are associated with smoking. However, among people who have never smoked, adenocarcinoma is the most common form of lung cancer. Elevated expression of ITGA11 was reported in non-small cells carcinomas and associated with stromal fibroblasts. The possible involvement of integrin α11 in other types of tumor-stroma interactions remains to be defined.
Prognosis
The overall 5-year survival rate of lung cancer is 15%. In NSCLC, survival rate is primarily determined by the tumor stage, i.e. the extend of spread of tumor cells at the time of diagnosis.
Oncogenesis
Interactions of tumor cells with the stroma play a critical role in tumor growth, invasion, metastases, angiogenesis, and chemoresistance. Factors derived from the carcinoma-associated fibroblast (CAF) or activated fibroblast can contribute to the transformation of epithelial cells and enhance the tumorigenicity of cancer cells possibly through paracrine secretion of growth factors. It was recently shown that CAFs in NSCLC express higher levels of integrin α11. One of the factors which is affected by higher levels of ITGA11 during tumor growth is IGF2. Higher levels of IGF2 in turn can stimulate growth of the tumor epithelial cells leading to tumor progression and metastasis.

Bibliography

Pubmed IDLast YearTitleAuthors
170165812006Great potential of a panel of multiple hMTH1, SPD, ITGA11 and COL11A1 markers for diagnosis of patients with non-small cell lung cancer.Chong IW et al
167647522006Second-line treatment for advanced-stage non-small-cell lung cancer: current and future options.Ho C et al
163009382006Tandem Sp1/Sp3 sites together with an Ets-1 site cooperate to mediate alpha11 integrin chain expression in mesenchymal cells.Lu N et al
161124282006Cytogenetic and molecular aspects of lung cancer.Panani AD et al
175811342007Physiology and pathology of collagen receptors.Popova SN et al
151837242004The mesenchymal alpha11beta1 integrin attenuates PDGF-BB-stimulated chemotaxis of embryonic fibroblasts on collagens.Popova SN et al
166090632006Cell-surface association between matrix metalloproteinases and integrins: role of the complexes in leukocyte migration and cancer progression.Stefanidakis M et al
172900662007Lung cancer in never smokers: a review.Subramanian J et al
115185102001alpha11beta1 integrin is a receptor for interstitial collagens involved in cell migration and collagen reorganization on mesenchymal nonmuscle cells.Tiger CF et al
104643111999cDNA cloning and chromosomal localization of human alpha(11) integrin. A collagen-binding, I domain-containing, beta(1)-associated integrin alpha-chain present in muscle tissues.Velling T et al
123868232002Novel candidate tumor marker genes for lung adenocarcinoma.Wang KK et al
123927622002Analysis of the human integrin alpha11 gene (ITGA11) and its promoter.Zhang WM et al
176000882007Integrin alpha 11 regulates IGF2 expression in fibroblasts to enhance tumorigenicity of human non-small-cell lung cancer cells.Zhu CQ et al

Other Information

Locus ID:

NCBI: 22801
MIM: 604789
HGNC: 6136
Ensembl: ENSG00000137809

Variants:

dbSNP: 22801
ClinVar: 22801
TCGA: ENSG00000137809
COSMIC: ITGA11

RNA/Proteins

Gene IDTranscript IDUniprot
ENSG00000137809ENST00000315757Q9UKX5
ENSG00000137809ENST00000423218Q9UKX5

Expression (GTEx)

0
50
100
150
200

Pathways

PathwaySourceExternal ID
Focal adhesionKEGGko04510
ECM-receptor interactionKEGGko04512
Regulation of actin cytoskeletonKEGGko04810
Focal adhesionKEGGhsa04510
ECM-receptor interactionKEGGhsa04512
Regulation of actin cytoskeletonKEGGhsa04810
Hypertrophic cardiomyopathy (HCM)KEGGko05410
Hypertrophic cardiomyopathy (HCM)KEGGhsa05410
Arrhythmogenic right ventricular cardiomyopathy (ARVC)KEGGko05412
Arrhythmogenic right ventricular cardiomyopathy (ARVC)KEGGhsa05412
Dilated cardiomyopathyKEGGko05414
Dilated cardiomyopathyKEGGhsa05414
PI3K-Akt signaling pathwayKEGGhsa04151
PI3K-Akt signaling pathwayKEGGko04151
Extracellular matrix organizationREACTOMER-HSA-1474244
Integrin cell surface interactionsREACTOMER-HSA-216083

Protein levels (Protein atlas)

Not detected
Low
Medium
High

References

Pubmed IDYearTitleCitations
185198262008Molecular genetics of successful smoking cessation: convergent genome-wide association study results.130
203796142010Personalized smoking cessation: interactions between nicotine dose, dependence and quit-success genotype score.62
176000882007Integrin alpha 11 regulates IGF2 expression in fibroblasts to enhance tumorigenicity of human non-small-cell lung cancer cells.59
189907042008Identification of the first prokaryotic collagen sequence motif that mediates binding to human collagen receptors, integrins alpha2beta1 and alpha11beta1.40
217961582011Integrins α2β1 and α11β1 regulate the survival of mesenchymal stem cells on collagen I.38
228696162012α11 integrin stimulates myofibroblast differentiation in diabetic cardiomyopathy.36
124962642003alpha 11beta 1 integrin recognizes the GFOGER sequence in interstitial collagens.29
197891902009A gene-based risk score for lung cancer susceptibility in smokers and ex-smokers.23
193905752009Lung cancer susceptibility model based on age, family history and genetic variants.20
196411492009A role for alpha11beta1 integrin in the human periodontal ligament.13

Citation

Svetlana N Popova ; Donald Gullberg

ITGA11 (integrin, alpha 11)

Atlas Genet Cytogenet Oncol Haematol. 2008-04-01

Online version: http://atlasgeneticsoncology.org/gene/41001/itga11