CDB20:0002872 PLA2G2A — ITGB1

Experimentally validated in Human; Orthology-inferred in Mouse, Rat, Frog, Chicken, Macaque, Pig, Cow, Chimp, Horse, Marmoset, Sheep

Title

Journal:; Year Published:

Abstract

Pro-inflammatory secretory phospholipase A2 type IIA binds to integrins alphavbeta3 and alpha4beta1 and induces proliferation of monocytic cells in an integrin-dependent manner.

The Journal of biological chemistry, 2008; PubMed, Homo sapiens PLA2G2A — Homo sapiens ITGB1

ABSTRACT: Secretory phospholipase A2 group IIA (sPLA2-IIA) plays an important role in the pathogenesis of inflammatory diseases. Catalytic activity of this enzyme that generates arachidonic acid is a major target for development of anti-inflammatory agents. Independent of its catalytic activity, sPLA2-IIA induces pro-inflammatory signals in a receptor-mediated mechanism (e.g. through the M-type receptor). However, the M-type receptor is species-specific: sPLA2-IIA binds to the M-type receptor in rodents and rabbits, but not in human. Thus sPLA2-IIA receptors in human have not been established. Here we demonstrated that sPLA2-IIA bound to integrin alphavbeta3 at a high affinity (K(D)=2 x 10(-7) M). We identified amino acid residues in sPLA2-IIA (Arg-74 and Arg-100) that are critical for integrin binding using docking simulation and mutagenesis. The integrin-binding site did not include the catalytic center or the M-type receptor-binding site. sPLA2-IIA also bound to alpha4beta1. We showed that sPLA2-IIA competed with VCAM-1 for binding to alpha4beta1, and bound to a site close to those for VCAM-1 and CS-1 in the alpha4 subunit. Wild type and the catalytically inactive H47Q mutant of sPLA2-IIA induced cell proliferation and ERK1/2 activation in monocytic cells, but the integrin binding-defective R74E/R100E mutant did not. This indicates that integrin binding is required, but catalytic activity is not required, for sPLA2-IIA-induced proliferative signaling. These results suggest that integrins alphavbeta3 and alpha4beta1 may serve as receptors for sPLA2-IIA and mediate pro-inflammatory action of sPLA2-IIA, and that integrin-sPLA2-IIA interaction is a novel therapeutic target.

Proinflammatory secreted phospholipase A2 type IIA (sPLA-IIA) induces integrin activation through direct binding to a newly identified binding site (site 2) in integrins αvβ3, α4β1, and α5β1.

The Journal of biological chemistry, 2015; PubMed, Homo sapiens PLA2G2A — Homo sapiens ITGB1

ABSTRACT: Integrins are activated by signaling from inside the cell (inside-out signaling) through global conformational changes of integrins. We recently discovered that fractalkine activates integrins in the absence of CX3CR1 through the direct binding of fractalkine to a ligand-binding site in the integrin headpiece (site 2) that is distinct from the classical RGD-binding site (site 1). We propose that fractalkine binding to the newly identified site 2 induces activation of site 1 though conformational changes (in an allosteric mechanism). We reasoned that site 2-mediated activation of integrins is not limited to fractalkine. Human secreted phospholipase A2 type IIA (sPLA2-IIA), a proinflammatory protein, binds to integrins αvβ3 and α4β1 (site 1), and this interaction initiates a signaling pathway that leads to cell proliferation and inflammation. Human sPLA2-IIA does not bind to M-type receptor very well. Here we describe that sPLA2-IIA directly activated purified soluble integrin αvβ3 and transmembrane αvβ3 on the cell surface. This activation did not require catalytic activity or M-type receptor. Docking simulation predicted that sPLA2-IIA binds to site 2 in the closed-headpiece of αvβ3. A peptide from site 2 of integrin β1 specifically bound to sPLA2-IIA and suppressed sPLA2-IIA-induced integrin activation. This suggests that sPLA2-IIA activates αvβ3 through binding to site 2. sPLA2-IIA also activated integrins α4β1 and α5β1 in a site 2-mediated manner. We recently identified small compounds that bind to sPLA2-IIA and suppress integrin-sPLA2-IIA interaction (e.g. compound 21 (Cmpd21)). Cmpd21 effectively suppressed sPLA2-IIA-induced integrin activation. These results define a novel mechanism of proinflammatory action of sPLA2-IIA through integrin activation.

Basic Information on PLA2G2A

Ligand Name: phospholipase A2 group IIA

Other Symbols: PLA2B, PLA2L

Ligand Location: secreted based on perplexity, uniprot, cell membrane based on uniprot

HGNC Gene Symbol Report: PLA2G2A

GeneCards: PLA2G2A

HGNC Gene Group: Phospholipases

Functional Annotations for PLA2G2A

Gene Ontologies: PAN-GO, AmiGO 2

Expression Profile: Human Protein Atlas (RNA and protein), Human Cell Atlas (RNA), GEPIA cancer vs normal (RNA), GeneCards (RNA and protein)

Disease Annotations: MalaCards, OMIM, Open Targets Platform, DISEASES (text mining), AI summary (LLM)

Interactions with other Receptors for PLA2G2A

PLA2G2A — ITGA4 ・ PLA2G2A — ITGA5 ・ PLA2G2A — ITGAV ・ PLA2G2A — ITGB3 ・ PLA2G2A — EGFR ・ PLA2G2A — ERBB2 ・ PLA2G2A — ERBB3

Basic Information on ITGB1

Receptor Name: integrin subunit beta 1

Other Symbols: FNRB, MSK12, MDF2, CD29, GPIIA

Receptor Location: cell membrane based on hpa, perplexity, uniprot

HGNC Gene Symbol Report: ITGB1

GeneCards: ITGB1

HGNC Gene Group: CD molecules, Integrins

Functional Annotations for ITGB1

Gene Ontologies: PAN-GO, AmiGO 2

Expression Profile: Human Protein Atlas (RNA and protein), Human Cell Atlas (RNA), GEPIA cancer vs normal (RNA), GeneCards (RNA and protein)

Disease Annotations: MalaCards, OMIM, Open Targets Platform, DISEASES (text mining), AI summary (LLM)

Interactions with other Ligands for ITGB1

ADAM12 — ITGB1 ・ ADAM15 — ITGB1 ・ ADAM17 — ITGB1 ・ ADAM2 — ITGB1 ・ ADAM9 — ITGB1 ・ ANGPT1 — ITGB1 ・ CD14 — ITGB1 ・ CHAD — ITGB1 ・ COL11A1 — ITGB1 ・ COL18A1 — ITGB1 ・ COL1A1 — ITGB1 ・ COL1A2 — ITGB1 ・ COL2A1 — ITGB1 ・ COL3A1 — ITGB1 ・ COL4A1 — ITGB1 ・ COL4A3 — ITGB1 ・ COL4A4 — ITGB1 ・ COL4A5 — ITGB1 ・ COL4A6 — ITGB1 ・ COL5A1 — ITGB1 ・ CXCL12 — ITGB1 ・ F13A1 — ITGB1 ・ FBLN1 — ITGB1 ・ FBN1 — ITGB1 ・ FGA — ITGB1 ・ VEGFD — ITGB1 ・ FN1 — ITGB1 ・ HSPG2 — ITGB1 ・ ICAM4 — ITGB1 ・ LAMA1 — ITGB1 ・ LAMA2 — ITGB1 ・ LAMA4 — ITGB1 ・ LAMA5 — ITGB1 ・ LAMB1 — ITGB1 ・ LAMB3 — ITGB1 ・ LAMC1 — ITGB1 ・ LAMC2 — ITGB1 ・ LGALS3BP — ITGB1 ・ MATN1 — ITGB1 ・ MDK — ITGB1 ・ NID1 — ITGB1 ・ NPNT — ITGB1 ・ PLG — ITGB1 ・ RELN — ITGB1 ・ SEMA7A — ITGB1 ・ SPP1 — ITGB1 ・ TGM2 — ITGB1 ・ THBS1 — ITGB1 ・ THBS2 — ITGB1 ・ TIMP2 — ITGB1 ・ TNC — ITGB1 ・ VCAM1 — ITGB1 ・ VCAN — ITGB1 ・ VEGFA — ITGB1 ・ VEGFC — ITGB1 ・ VTN — ITGB1 ・ ANGPTL2 — ITGB1 ・ CCN4 — ITGB1 ・ CLEC11A — ITGB1 ・ LGALS1 — ITGB1 ・ SPON2 — ITGB1 ・ ADAM28 — ITGB1 ・ AGGF1 — ITGB1 ・ AGRN — ITGB1 ・ ANGPT2 — ITGB1 ・ ANGPTL4 — ITGB1 ・ CCN2 — ITGB1 ・ CCN3 — ITGB1 ・ CD40LG — ITGB1 ・ CDH1 — ITGB1 ・ COL10A1 — ITGB1 ・ COL11A2 — ITGB1 ・ COL13A1 — ITGB1 ・ COL4A2 — ITGB1 ・ COL8A1 — ITGB1 ・ COL8A2 — ITGB1 ・ CSPG4 — ITGB1 ・ CX3CL1 — ITGB1 ・ ICAM5 — ITGB1 ・ IL1B — ITGB1 ・ JAM2 — ITGB1 ・ L1CAM — ITGB1 ・ LAMA3 — ITGB1 ・ LAMB2 — ITGB1 ・ LGALS3 — ITGB1 ・ LGALS8 — ITGB1 ・ MFGE8 — ITGB1 ・ MIA — ITGB1 ・ NTN4 — ITGB1 ・ PLAUR — ITGB1 ・ SVEP1 — ITGB1 ・ TGFB1 — ITGB1 ・ TGFB3 — ITGB1 ・ THBS4 — ITGB1 ・ THY1 — ITGB1 ・ TIMP1 — ITGB1 ・ VWF — ITGB1