Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Short form of α9 promotes α9β1 integrin-dependent cell adhesion by modulating the function of the full-length α9 subunit.

ABSTRACT: The α9β1 integrin is a multifunctional receptor that interacts with a variety of ligands including vascular cell adhesion molecule 1, tenascin-C, and osteopontin. A 2.3-kb truncated form of α9 integrin subunit cDNA was identified by searching the Medline database. This splice variant, which we called the short form of α9 integrin (SFα9), encodes a 632-aa isoform lacking transmembrane and cytoplasmic domains, and its authentic expression was verified by PCR and Western blotting. SFα9 is expressed on the cell surface but cannot bind ligand in the absence of the full-length α9 subunit. Over-expression of SFα9 in cells expressing full-length α9 promotes α9-dependent cell adhesion. This promoting effect of SFα9 requires the authentic cytoplasmic domain of the co-expressed full-length α9 subunit. Thus, SFα9 is a novel functional modulator of α9β1 integrin by inside-out signaling.

SUBMITTER: Kon S

PROVIDER: S-EPMC3118859 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Short form of α9 promotes α9β1 integrin-dependent cell adhesion by modulating the function of the full-length α9 subunit.

Kon Shigeyuki S Atakilit Amha A Sheppard Dean D

Experimental cell research 20110416 12

The α9β1 integrin is a multifunctional receptor that interacts with a variety of ligands including vascular cell adhesion molecule 1, tenascin-C, and osteopontin. A 2.3-kb truncated form of α9 integrin subunit cDNA was identified by searching the Medline database. This splice variant, which we called the short form of α9 integrin (SFα9), encodes a 632-aa isoform lacking transmembrane and cytoplasmic domains, and its authentic expression was verified by PCR and Western blotting. SFα9 is expressed ...[more]

PMID: 21515257

Similar Datasets

Analysis of gene expression changes upon ZBTB18 full length (FL), ZBTB18 full length-mutant (FL-mut), ZBTB18 short form Nte (SF-Nte) and ZBTB18 short form Nte (SF-mut) in SNB19 glioblastoma cell line

Project description:ZBTB18 is a transcriptional repressor and tumor suppressor in glioblastoma (GBM). Specifically, it acts as a repressor of mesenchymal genes. ZBTB18 interacts with C-terminal binding proteins 1 and 2 through a VLDL motif. In GBM, ZBTB18 is cleaved the the calpain 2 intracellular proteases which generates truncated Nte and Cte short forms. Here we have investigated gene expression changes which occur upon the expression of ZBTB18 full lenght or ZBTB18 short form Nte (SF-Nte), as well as upon expression of the mutated counterparts which no longer interacts with CTBP1/2.

2022-06-20 | GSE184890 | GEO

Coarse-Grained Simulation of Full-Length Integrin Activation.

Project description:Integrin conformational dynamics are critical to their receptor and signaling functions in many cellular processes, including spreading, adhesion, and migration. However, assessing integrin conformations is both experimentally and computationally challenging because of limitations in resolution and dynamic sampling. Thus, structural changes that underlie transitions between conformations are largely unknown. Here, focusing on integrin αvβ3, we developed a modified form of the coarse-grained heterogeneous elastic network model (hENM), which allows sampling conformations at the onset of activation by formally separating local fluctuations from global motions. Both local fluctuations and global motions are extracted from all-atom molecular dynamics simulations of the full-length αvβ3 bent integrin conformer, but whereas the former are incorporated in the hENM as effective harmonic interactions between groups of residues, the latter emerge by systematically identifying and treating weak interactions between long-distance domains with flexible and anharmonic connections. The new hENM model allows integrins and single-point mutant integrins to explore various conformational states, including the initiation of separation between α- and β-subunit cytoplasmic regions, headpiece extension, and legs opening.

| S-EPMC6428961 | biostudies-literature

Polydom/SVEP1 is a ligand for integrin α9β1.

Project description:A variety of proteins, including tenascin-C and osteopontin, have been identified as ligands for integrin α9β1. However, their affinities for integrin α9β1 are apparently much lower than those of other integrins (e.g. α3β1, α5β1, and α8β1) for their specific ligands, leaving the possibility that physiological ligands for integrin α9β1 still remain unidentified. In this study, we found that polydom (also named SVEP1) mediates cell adhesion in an integrin α9β1-dependent manner and binds directly to recombinant integrin α9β1 with an affinity that far exceeds those of the known ligands. Using a series of recombinant polydom proteins with N-terminal deletions, we mapped the integrin-binding site to the 21st complement control protein domain. Alanine-scanning mutagenesis revealed that the EDDMMEVPY sequence (amino acids 2636-2644) in the 21st complement control protein domain was involved in the binding to integrin α9β1 and that Glu(2641) was the critical acidic residue for the integrin binding. The importance of this sequence was further confirmed by integrin binding inhibition assays using synthetic peptides. Immunohistochemical analyses of mouse embryonic tissues showed that polydom colocalized with integrin α9 in the stomach, intestine, and other organs. Furthermore, in situ integrin α9β1 binding assays using frozen mouse tissues showed that polydom accounts for most, but not all, of the integrin α9β1 ligands in tissues. Taken together, the present findings indicate that polydom is a hitherto unknown ligand for integrin α9β1 that functions as a physiological ligand in vivo.

| S-EPMC3408197 | biostudies-literature

Genetic ablation of myeloid integrin α9 attenuates early atherosclerosis.

Project description:Integrin α9β1 is known to stabilize leukocyte adhesion to the activated endothelium. We determined the role of myeloid cell α9β1 in early atherosclerosis in two models: α9Mye-KOApoe-/- or the Ldlr-/- mice transplanted with bone marrow (BM) from α9Mye-KO mice fed a high-fat "Western" diet for 4 wk. α9Mye-KOApoe-/- mice exhibited reduced early lesions in the aortae and aortic sinuses (P < 0.05 vs α9WT Apoe-/- mice). Similar results were obtained in α9Mye-KO BM→Ldlr-/- mice (P < 0.05 vs α9WT BM→Ldlr-/- mice). Reduced early atherosclerosis in α9Mye-KOApoe-/- mice was associated with decreased neutrophil and neutrophil extracellular traps (NETs) content in the aortic lesions (P < 0.05 vs α9WTApoe-/-). Vascular cell adhesion molecule-1-stimulated neutrophils from α9Mye-KO mice exhibited reduced adhesion, transmigration, and NETs formation (NETosis) (P < 0.05 vs α9WT neutrophils). Reduced NETosis was associated with decreased extracellular signal-regulated kinase phosphorylation, peptidyl arginine deiminase 4, and citrullinated histone H3 expression. In summary, genetic ablation of myeloid cell-specific α9 reduces early atherosclerosis, most likely by reducing neutrophil adhesion, transmigration, and NETosis.

| S-EPMC11531806 | biostudies-literature

Integrin α9β1 in airway smooth muscle suppresses exaggerated airway narrowing.

Project description:Exaggerated contraction of airway smooth muscle is the major cause of symptoms in asthma, but the mechanisms that prevent exaggerated contraction are incompletely understood. Here, we showed that integrin α9β1 on airway smooth muscle localizes the polyamine catabolizing enzyme spermidine/spermine N1-acetyltransferase (SSAT) in close proximity to the lipid kinase PIP5K1γ. As PIP5K1γ is the major source of PIP2 in airway smooth muscle and its activity is regulated by higher-order polyamines, this interaction inhibited IP3-dependent airway smooth muscle contraction. Mice lacking integrin α9β1 in smooth muscle had increased airway responsiveness in vivo, and loss or inhibition of integrin α9β1 increased in vitro airway narrowing and airway smooth muscle contraction in murine and human airways. Contraction was enhanced in control airways by the higher-order polyamine spermine or by cell-permeable PIP2, but these interventions had no effect on airways lacking integrin α9β1 or treated with integrin α9β1-blocking antibodies. Enhancement of SSAT activity or knockdown of PIP5K1γ inhibited airway contraction, but only in the presence of functional integrin α9β1. Therefore, integrin α9β1 appears to serve as a brake on airway smooth muscle contraction by recruiting SSAT, which facilitates local catabolism of polyamines and thereby inhibits PIP5K1γ. Targeting key components of this pathway could thus lead to new treatment strategies for asthma.

| S-EPMC3448403 | biostudies-literature

Full-length RNA-seq of short RNAs from Cuscuta campestris

Project description:Cuscuta campestris is an obligate parasitic plant that attaches to the stems of host plants to obtain water and nutrients. C. campestris produces a specialized set of microRNAs specifically at the host-parasite interface. Many of these interface-induced microRNAs target mRNAs from the host. This experiment was designed to capture full-length primary transcripts that give rise to C. campestris interface-induced microRNAs. C. campestris shoot tips were stimulated to produce haustoria, then harvested to extract total RNA. RNA was then treated with various enzymes to modify 5' ends. Libraries were then made and sequenced. Importantly the library method only captures RNAs with a 5'-monophosphate. Therefore the specific enzymatic treatments can reveal the native 5' ends of the sequenced RNAs. Data were used to identify the primary transcripts for many of the known C. campestris primary microRNA transcripts. The data were also interrogated to tally specific snRNAs (U1, U2, U4, and U5) that are known to have a 2,2,7mGppp cap, and the tally pre-tRNAs, which are known to have a ppp 5' end. The analyzed results indicated that C. campestris interface-induced microRNA primary transcripts likely have a 5' ppp, not a cap, consistent with transcription by RNA polymerase III. The analysis also demonstrated that C. campestris interface-induced microRNA primary transcripts mostly terminate within stretches of polyT and lack polyA tails, also features consistent with Pol III transcription. Finally, the analysis indicated that the transcriptional start sites were located ~ 55 bp downstream of a common ten-base pair promoter element (the upstream sequence element). The 55bp spacing is also consistent with Pol III transcription.

2023-01-03 | GSE221347 | GEO

α9β1 integrin & its ligands as new potential biomarkers in FMF.

Project description:Background & objectives Familial Mediterranean Fever (FMF) manifests as a hereditary condition characterized by repeated bouts of fever, abdominal, chest, and joint discomfort, and swelling. Colchicine is the most common form of treatment, but it does not eliminate the disease. The underlying causes of the inflammatory mechanism are still not fully known. Methods A total of 20 healthy controls, 16 individuals with FMF in the attack period, and 14 in the remission period participated in the study. ITGA9, ITGB1, OPN, TNC, VEGF, VCAM-1, TGM2, TSP-1, Emilin-1, and vWF levels were measured by ELISA by obtaining serum from blood samples of individuals. In addition, gene expressions of α9β1 (ITGA9, ITGB1) and its best known ligands (TNC, SPP1) were analyzed by quantitative real-time PCR (qPCR). Results The findings of this study showed that serum levels of α9β1 and its ligands were higher in individuals with FMF in the attack period than in the healthy controls and the FMF group in the remission period (P<0.05). The marker levels of the healthy group were also higher than those in the remission period (p<0.05). In addition, when the gene expressions were compared between the healthy controls and FMF group, no significant difference was found for ITGA9, ITGB1, TNC, and SPP1 genes. Interpretation & conclusions The function of α9β1 and its ligands in FMF disease was investigated for the first time in this study as per our knowledge. Serum levels of these biomarkers may help identify potential new targets for FMF disease diagnosis and treatment approaches.

| S-EPMC11463857 | biostudies-literature

Targeting myeloid-cell specific integrin α9β1 inhibits arterial thrombosis in mice.

Project description:Evidence suggests that neutrophils contribute to thrombosis via several mechanisms, including neutrophil extracellular traps (NETs) formation. Integrin α9β1 is highly expressed on neutrophils when compared with monocytes. It undergoes affinity upregulation on neutrophil activation, and stabilizes adhesion to the activated endothelium. The role of integrin α9 in arterial thrombosis remains unexplored. We generated novel myeloid cell-specific integrin α9-/- mice (α9fl/flLysMCre+) to study the role of integrin α9 in arterial thrombosis. α9fl/fl littermates were used as controls. We report that α9fl/flLysMCre+ mice were less susceptible to arterial thrombosis in ferric chloride (FeCl3) and laser injury-induced thrombosis models with unaltered hemostasis. Neutrophil elastase-positive cells were significantly reduced in α9fl/flLysMCre+ mice concomitant with reduction in neutrophil count, myeloperoxidase levels, and red blood cells in the FeCl3 injury-induced carotid thrombus. The percentage of cells releasing NETs was significantly reduced in α9fl/flLysMCre+ mouse neutrophils stimulated with thrombin-activated platelets. Furthermore, we found a significant decrease in neutrophil-mediated platelet aggregation and cathepsin-G secretion in α9fl/flLysMCre+ mice. Transfusion of α9fl/fl neutrophils in α9fl/flLysMCre+ mice restored thrombosis similar to α9fl/fl mice. Treatment of wild-type mice with anti-integrin α9 antibody inhibited arterial thrombosis. This study identifies the potential role of integrin α9 in modulating arterial thrombosis.

| S-EPMC7068033 | biostudies-literature

Full-length αIIbβ3 CryoEM structure reveals intact integrin initiate-activation intrinsic architecture.

Project description:Integrin αIIbβ3 is the key receptor regulating platelet retraction and accumulation, thus pivotal for hemostasis, and arterial thrombosis as well as a proven drug-target for antithrombotic therapies. Here we resolve the cryoEM structures of the intact full-length αIIbβ3, which covers three distinct states along the activation pathway. Here, we resolve intact αIIbβ3 structure at 3Å resolution, revealing the overall topology of the heterodimer with the transmembrane (TM) helices and the head region ligand-binding domain tucked in a specific angle proximity to the TM region. In response to the addition of an Mn2+ agonist, we resolved two coexisting states, "intermediate" and "pre-active". Our structures show conformational changes of the intact αIIbβ3 activating trajectory, as well as a unique twisting of the lower integrin legs representing intermediate state (TM region at a twisting conformation) integrin and a coexisting pre-active state (bent and opening in leg), which is required for inducing the transitioning platelets to accumulate. Our structure provides for the first time direct structural evidence for the lower legs' involvement in full-length integrin activation mechanisms. Additionally, our structure offers a new strategy to target the αIIbβ3 lower leg allosterically instead of modulating the affinity of the αIIbβ3 head region.

| S-EPMC9980189 | biostudies-literature

Two modes of integrin activation form a binary molecular switch in adhesion maturation.

Project description:Talin-mediated integrin activation drives integrin-based adhesions. Here we examine the roles of two proteins that induce talin-integrin interactions--vinculin and Rap1-GTP-interacting adaptor molecule (RIAM)--in the formation and maturation of integrin-based adhesions. RIAM-containing adhesions are primarily in the lamellipodium; RIAM is subsequently reduced in mature focal adhesions due to direct competition with vinculin for talin-binding sites. We show that vinculin binding to talin induces Rap1-independent association of talin with integrins and resulting integrin activation, in sharp contrast to Rap1-dependent RIAM-induced activation. Vinculin stabilizes adhesions, increasing their ability to transmit force, whereas RIAM played a critical role in lamellipodial protrusion. Thus displacement of RIAM by vinculin acts as a molecular switch that mediates the transition of integrin-based adhesions from drivers of lamellipodial protrusion to stable, force-bearing adhesions. Consequently changes in the abundance of two multiprotein modules within maturing adhesions, one regulated by Rap1 and one by tension, result in the temporal evolution of adhesion functions.

| S-EPMC3639047 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data