Key Spec Table
|Species Reactivity||Key Applications||Host||Format||Antibody Type|
|H, M||ICC, IP, WB||Rb||Purified||Polyclonal Antibody|
|Presentation||Protein A Purified immunoglobulin in 0.07M Tris-glycine, pH 7.4, 0.105 M NaCl, 0.035% sodium azide as a preservative.|
|Application||This Anti-Pyk2 Antibody is validated for use in IC, IP, WB for the detection of Pyk2.|
|Safety Information according to GHS|
|Storage and Shipping Information|
|Storage Conditions||Stable for 1 year at 2-8°C from date of receipt.|
|Material Size||250 µg|
|Anti-Pyk2 (rabbit polyclonal IgG)||2884538|
|Anti-Pyk2 - 2424764||2424764|
|Anti-Pyk2 - 15306||15306|
|Anti-Pyk2 - 17748||17748|
|Anti-Pyk2 - 20648||20648|
|Anti-Pyk2 - 2278504||2278504|
|Anti-Pyk2 - 2510371||2510371|
|Anti-Pyk2 - 26172||26172|
|Reference overview||Application||Pub Med ID|
|HBZ stimulates brain-derived neurotrophic factor/TrkB autocrine/paracrine signaling to promote survival of human T-cell leukemia virus type 1-Infected T cells.|
Polakowski, N; Terol, M; Hoang, K; Nash, I; Laverdure, S; Gazon, H; Belrose, G; Mesnard, JM; Césaire, R; Péloponèse, JM; Lemasson, I
Journal of virology 88 13482-94 2014
Brain-derived neurotrophic factor (BDNF) is a neurotrophin that promotes neuronal proliferation, survival, and plasticity. These effects occur through autocrine and paracrine signaling events initiated by interactions between secreted BDNF and its high-affinity receptor, TrkB. A BDNF/TrkB autocrine/paracrine signaling loop has additionally been implicated in augmenting the survival of cells representing several human cancers and is associated with poor patient prognosis. Adult T-cell leukemia (ATL) is a fatal malignancy caused by infection with the complex retrovirus human T-cell leukemia virus type 1 (HTLV-1). In this study, we found that the HTLV-1-encoded protein HBZ activates expression of BDNF, and consistent with this effect, BDNF expression is elevated in HTLV-1-infected T-cell lines compared to uninfected T cells. Expression of TrkB is also higher in HTLV-1-infected T-cell lines than in uninfected T cells. Furthermore, levels of both BDNF and TrkB mRNAs are elevated in peripheral blood mononuclear cells (PBMCs) from ATL patients, and ATL patient sera contain higher concentrations of BDNF than sera from noninfected individuals. Finally, chemical inhibition of TrkB signaling increases apoptosis in HTLV-1-infected T cells and reduces phosphorylation of glycogen synthase kinase 3β (GSK-3β), a downstream target in the signaling pathway. These results suggest that HBZ contributes to an active BDNF/TrkB autocrine/paracrine signaling loop in HTLV-1-infected T cells that enhances the survival of these cells.Infection with human T-cell leukemia virus type 1 (HTLV-1) can cause a rare form of leukemia designated adult T-cell leukemia (ATL). Because ATL patients are unresponsive to chemotherapy, this malignancy is fatal. As a retrovirus, HTLV-1 integrates its genome into a host cell chromosome in order to utilize host factors for replication and expression of viral proteins. However, in infected cells from ATL patients, the viral genome is frequently modified to block expression of all but a single viral protein. This protein, known as HBZ, is therefore believed to modulate cellular pathways necessary for the leukemic state and the chemotherapeutic resistance of the cell. Here we provide evidence to support this hypothesis. We found that HBZ promotes a BDNF/TrkB autocrine/paracrine signaling pathway that is known to enhance the survival and chemotherapeutic resistance of other types of cancer cells. It is possible that inhibition of this pathway may improve treatments for ATL.
|Collagen XV inhibits epithelial to mesenchymal transition in pancreatic adenocarcinoma cells.|
Clementz, AG; Mutolo, MJ; Leir, SH; Morris, KJ; Kucybala, K; Harris, H; Harris, A
PloS one 8 e72250 2013
Collagen XV (COLXV) is a secreted non-fibrillar collagen found within basement membrane (BM) zones of the extracellular matrix (ECM). Its ability to alter cellular growth in vitro and to reduce tumor burden and increase survival in vivo support a role as a tumor suppressor. Loss of COLXV during the progression of several aggressive cancers precedes basement membrane invasion and metastasis. The resultant lack of COLXV subjacent to the basement membrane and subsequent loss of its interactions with other proteins in this zone may directly impact tumor progression. Here we show that COLXV significantly reduces invasion of pancreatic adenocarcinoma cells through a collagen I (COLI) matrix. Moreover, we demonstrate that epithelial to mesenchymal transition (EMT) in these cells, which is recapitulated in vitro by cell scattering on a COLI substrate, is inhibited by over-expression of COLXV. We identify critical collagen-binding surface receptors on the tumor cells, including the discoidin domain receptor 1 (DDR1) and E-Cadherin (E-Cad), which interact with COLXV and appear to mediate its function. In the presence of COLXV, the intracellular redistribution of E-Cad from the cell periphery, which is associated with COLI-activated EMT, is inhibited and concurrently, DDR1 signaling is suppressed. Furthermore, continuous exposure of the pancreatic adenocarcinoma cells to high levels of COLXV suppresses endogenous levels of N-Cadherin (N-Cad). These data reveal a novel mechanism whereby COLXV can function as a tumor suppressor in the basement membrane zone.
|p21 as a transcriptional co-repressor of S-phase and mitotic control genes.|
Ferrándiz, N; Caraballo, JM; García-Gutierrez, L; Devgan, V; Rodriguez-Paredes, M; Lafita, MC; Bretones, G; Quintanilla, A; Muñoz-Alonso, MJ; Blanco, R; Reyes, JC; Agell, N; Delgado, MD; Dotto, GP; León, J
PloS one 7 e37759 2012
It has been previously described that p21 functions not only as a CDK inhibitor but also as a transcriptional co-repressor in some systems. To investigate the roles of p21 in transcriptional control, we studied the gene expression changes in two human cell systems. Using a human leukemia cell line (K562) with inducible p21 expression and human primary keratinocytes with adenoviral-mediated p21 expression, we carried out microarray-based gene expression profiling. We found that p21 rapidly and strongly repressed the mRNA levels of a number of genes involved in cell cycle and mitosis. One of the most strongly down-regulated genes was CCNE2 (cyclin E2 gene). Mutational analysis in K562 cells showed that the N-terminal region of p21 is required for repression of gene expression of CCNE2 and other genes. Chromatin immunoprecipitation assays indicated that p21 was bound to human CCNE2 and other p21-repressed genes gene in the vicinity of the transcription start site. Moreover, p21 repressed human CCNE2 promoter-luciferase constructs in K562 cells. Bioinformatic analysis revealed that the CDE motif is present in most of the promoters of the p21-regulated genes. Altogether, the results suggest that p21 exerts a repressive effect on a relevant number of genes controlling S phase and mitosis. Thus, p21 activity as inhibitor of cell cycle progression would be mediated not only by the inhibition of CDKs but also by the transcriptional down-regulation of key genes.
|Decreased cell adhesion promotes angiogenesis in a Pyk2-dependent manner.|
Shen CJ, Raghavan S, Xu Z, Baranski JD, Yu X, Wozniak MA, Miller JS, Gupta M, Buckbinder L, Chen CS.
Experimental cell research 317 1860-71 2011
Angiogenesis is regulated by both soluble growth factors and cellular interactions with the extracellular matrix (ECM). While cell adhesion via integrins has been shown to be required for angiogenesis, the effects of quantitative changes in cell adhesion and spreading against the ECM remain less clear. Here, we show that angiogenic sprouting in natural and engineered three-dimensional matrices exhibited a biphasic response, with peak sprouting when adhesion to the matrix was limited to intermediate levels. Examining changes in global gene expression to determine a genetic basis for this response, we demonstrate a vascular endothelial growth factor (VEGF)-induced upregulation of genes associated with vascular invasion and remodeling when cell adhesion was limited, whereas cells on highly adhesive surfaces upregulated genes associated with proliferation. To explore a mechanistic basis for this effect, we turned to focal adhesion kinase (FAK), a central player in adhesion signaling previously implicated in angiogenesis, and its homologue, proline-rich tyrosine kinase 2 (Pyk2). While FAK signaling had some impact, our results suggested that Pyk2 can regulate both gene expression and endothelial sprouting through its enhanced activation by VEGF in limited adhesion contexts. We also demonstrate decreased sprouting of tissue explants from Pyk2-null mice as compared to wild type mice as further confirmation of the role of Pyk2 in angiogenic sprouting. These results suggest a surprising finding that limited cell adhesion can enhance endothelial responsiveness to VEGF and demonstrate a novel role for Pyk2 in the adhesive regulation of angiogenesis.
|The miR-17-92 microRNA cluster is regulated by multiple mechanisms in B-cell malignancies.|
Ji, M; Rao, E; Ramachandrareddy, H; Shen, Y; Jiang, C; Chen, J; Hu, Y; Rizzino, A; Chan, WC; Fu, K; McKeithan, TW
The American journal of pathology 179 1645-56 2011
A cluster of six microRNAs (miRNAs), miR-17-92, is processed from the transcript of C13orf25, a gene amplified in some lymphomas and solid tumors. We find that levels of the miRNAs in the cluster do not vary entirely in parallel with each other or with the primary RNA in B-cell lines or normal cells, suggesting that processing or stability of the miRNAs is differentially regulated. Using luciferase reporter assays, we identified the region required for maximum promoter activity. Additional deletions and mutations indicated that the promoter is regulated by the collaborative activity of several transcription factors, most of which individually have only a moderate effect; mutation of a cluster of putative SP1-binding sites, however, reduces promoter activity by 70%. MYC is known to regulate C13orf25; surprisingly, mutation of a putative promoter MYC-binding site enhanced promoter activity. We found that the inhibitory MYC family member MXI1 bound to this region. The chromatin structure of a greater than 22.5-kb region encompassing the gene contains peaks of activating histone marks, suggesting the presence of enhancers, and we confirmed that at least two regions have enhancer activity. Because the miR-17-92 cluster acts as an important oncogene in several cancers and targets genes important in regulating cell proliferation and survival, further studies of its transcriptional control are warranted.
|Luminal alkalinization attenuates proteinuria-induced oxidative damage in proximal tubular cells.|
Souma, T; Abe, M; Moriguchi, T; Takai, J; Yanagisawa-Miyazawa, N; Shibata, E; Akiyama, Y; Toyohara, T; Suzuki, T; Tanemoto, M; Abe, T; Sato, H; Yamamoto, M; Ito, S
Journal of the American Society of Nephrology : JASN 22 635-48 2011
A highly acidic environment surrounds proximal tubular cells as a result of their reabsorption of HCO(3)(-). It is unclear whether this luminal acidity affects proteinuria-induced progression of tubular cell damage. Here, we investigated the contribution of luminal acidity to superoxide (O(2)(·-)) production induced by oleic acid-bound albumin (OA-Alb) in proximal tubular cells. Acidic media significantly enhanced OA-Alb-induced O(2)(·-) production in the HK-2 proximal tubular cell line. Simultaneous treatment with both OA-Alb and acidic media led to phosphorylation of the intracellular pH sensor Pyk2. Highly phosphorylated Pyk2 associated with activation of Rac1, an essential subcomponent of NAD(P)H oxidase. Furthermore, knockdown of Pyk2 with siRNA attenuated the O(2)(·-) production induced by cotreatment with OA-Alb and acid. To assess whether luminal alkalinization abrogates proteinuria-induced tubular damage, we studied a mouse model of protein-overload nephropathy. NaHCO(3) feeding selectively alkalinized the urine and dramatically attenuated the accumulation of O(2)(·-)-induced DNA damage and proximal tubular injury. Overall, these observations suggest that luminal acidity aggravates proteinuria-induced tubular damage and that modulation of this acidic environment may hold potential as a therapeutic target for proteinuric kidney disease.
|Mad3 negatively regulates B cell differentiation in the spleen by inducing Id2 expression.|
Gore, Y; Lantner, F; Hart, G; Shachar, I
Molecular biology of the cell 21 1864-71 2010
Immature B cells migrate to the spleen where they differentiate into mature cells. This final maturation step is crucial to enable B cells to become responsive to antigens and to participate in the immune response. Previously, we showed that Id2 acts as a negative regulator of the differentiation of immature B cells occurring in the spleen. Id2 expression has been found to depend on Myc-Max-Mad transcriptional complexes in mammary epithelial cells. Nearly all studies to date have shown that Mad proteins inhibit proliferation, presumably by antagonizing the function of Myc proteins. In the current study, we followed the Mad family members during peripheral B cell differentiation. We show that Mad3 actively regulates B cell differentiation. Our results demonstrate that high expression levels of Mad3 in immature B cells induce Id2 expression, which inhibits transcription of genes essential for B cell differentiation. During their differentiation to mature cells, B cells reduce their Mad3 expression, enabling the maturation process to occur.Full Text Article
|Expression of a protein involved in bone resorption, Dkk1, is activated by HTLV-1 bZIP factor through its activation domain.|
Polakowski, N; Gregory, H; Mesnard, JM; Lemasson, I
Retrovirology 7 61 2010
Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia, a malignancy characterized by uncontrolled proliferation of virally-infected CD4+ T-cells. Hypercalcemia and bone lesions due to osteoclast-mediated bone resorption are frequently associated with more aggressive forms of the disease. The HTLV-1 provirus contains a unique antisense gene that expresses HTLV-1 basic leucine zipper (bZIP) factor (HBZ). HBZ is localized to the nucleus where it regulates levels of transcription by binding to certain cellular transcriptional regulators. Among its protein targets, HBZ forms a stable complex with the homologous cellular coactivators, p300 and CBP, which is modulated through two N-terminal LXXLL motifs in the viral protein and the conserved KIX domain in the coactivators.To determine the effects of these interactions on transcription, we performed a preliminary microarray analysis, comparing levels of gene expression in cells with wild-type HBZ versus cells with HBZ mutated in its LXXLL motifs. DKK1, which encodes the secreted Wnt signaling inhibitor, Dickkopf-1 (Dkk1), was confirmed to be transcriptionally activated by HBZ, but not its mutant. Dkk1 plays a major role in the development of bone lesions caused by multiple myeloma. In parallel with the initial findings, activation of Dkk1 expression by HBZ was abrogated by siRNA-mediated knockdown of p300/CBP or by a truncated form of p300 containing the KIX domain. Among HTLV-1-infected T-cell lines tested, the detection of Dkk1 mRNA partially correlated with a threshold level of HBZ mRNA. In addition, an uninfected and an HTLV-1-infected T-cell line transfected with an HBZ expression vector exhibited de novo and increased DKK1 transcription, respectively. In contrast to HBZ, The HTLV-1 Tax protein repressed Dkk1 expression.These data indicate that HBZ activates Dkk1 expression through its interaction with p300/CBP. However, this effect is limited in HTLV-1-infected T-cell lines, which in part, may be due to suppression of Dkk1 expression by Tax. Consequently, the ability of HBZ to regulate expression of Dkk1 and possibly other cellular genes may only be significant during late stages of ATL, when Tax expression is repressed.Full Text Article
|Pyk2 inhibition of p53 as an adaptive and intrinsic mechanism facilitating cell proliferation and survival.|
Ssang-Taek Lim,Nichol L G Miller,Ju-Ock Nam,Xiao Lei Chen,Yangmi Lim,David D Schlaepfer
The Journal of biological chemistry 285 2010
Pyk2 is a cytoplasmic tyrosine kinase related to focal adhesion kinase (FAK). Compensatory Pyk2 expression occurs upon FAK loss in mice. However, the impact of Pyk2 up-regulation remains unclear. Previous studies showed that nuclear-localized FAK promotes cell proliferation and survival through FAK FERM domain-enhanced p53 tumor suppressor degradation (Lim, S. T., Chen, X. L., Lim, Y., Hanson, D. A., Vo, T. T., Howerton, K., Larocque, N., Fisher, S. J., Schlaepfer, D. D., and Ilic, D. (2008) Mol. Cell 29, 9-22). Here, we show that FAK knockdown triggered p53 activation and G(1) cell cycle arrest in human umbilical vein endothelial cells after 4 days. However, by 7 days elevated Pyk2 expression occurred with a reduction in p53 levels and the release of the G(1) block under conditions of continued FAK knockdown. To determine whether Pyk2 regulates p53, experiments were performed in FAK(-/-)p21(-/-) mouse embryo fibroblasts expressing endogenous Pyk2 and in ID8 ovarian carcinoma cells expressing both Pyk2 and FAK. In both cell lines, Pyk2 knockdown increased p53 levels and inhibited cell proliferation associated with G(1) cell cycle arrest. Pyk2 FERM domain re-expression was sufficient to reduce p53 levels and promote increased BrdUrd incorporation. Pyk2 FERM promoted Mdm2-dependent p53 ubiquitination. Pyk2 FERM effects on p53 were blocked by proteasomal inhibition or mutational-inactivation of Pyk2 FERM nuclear localization. Staurosporine stress of ID8 cells promoted endogenous Pyk2 nuclear accumulation and enhanced Pyk2 binding to p53. Pyk2 knockdown potentiated ID8 cell death upon staurosporine addition. Moreover, Pyk2 FERM expression in human fibroblasts upon FAK knockdown prevented cisplatin-mediated apoptosis. Our studies demonstrate that nuclear Pyk2 functions to limit p53 levels, thus facilitating cell growth and survival in a kinase-independent manner.Full Text Article
|Epigenetic analysis of the critical region I for premature ovarian failure: demonstration of a highly heterochromatic domain on the long arm of the mammalian X chromosome.|
Rizzolio, F; Pramparo, T; Sala, C; Zuffardi, O; De Santis, L; Rabellotti, E; Calzi, F; Fusi, F; Bellazzi, R; Toniolo, D
Journal of medical genetics 46 585-92 2009
X chromosome rearrangements defined a critical region for premature ovarian failure (POF) that extended for greater than 15 Mb in Xq. It has been shown previously that the region could be divided into two functionally distinct portions and suggested that balanced translocations interrupting its proximal part, critical region 1 (CR1), could be responsible for POF through downregulation of ovary expressed autosomal genes translocated to the X chromosome.This study reports that such position effect can indeed be demonstrated by analysis of breakpoint regions in somatic cells of POF patients and by the finding that CR1 has a highly heterochromatic organisation, very different from that of the euchromatic autosomal regions involved in the rearrangements. The chromatin organisation of the POF CR1 is likely to be responsible for the epigenetic modifications observed in POF patients. The characteristics of CR1 and its downregulation in oocytes may very well explain its role in POF and the frequency of the POF phenotype in chromosomal rearrangements involving Xq. This study also demonstrates a large and evolutionary conserved domain of the long arm of the X chromosome, largely corresponding to CR1, that may have structural or functional roles, in oocyte maturation or in X chromosome inactivation.
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