Key Specifications Table
|Species Reactivity||Key Applications||Host||Format||Antibody Type|
|A||ELISA, WB||M||HRP||Monoclonal Antibody|
|Safety Information according to GHS|
|Material Size||10 blots|
References | 18 Available | See All References
|Reference overview||Application||Pub Med ID|
|Antagonistic interplay between necdin and Bmi1 controls proliferation of neural precursor cells in the embryonic mouse neocortex. |
Minamide, R; Fujiwara, K; Hasegawa, K; Yoshikawa, K
PloS one 9 e84460 2014
Neural precursor cells (NPCs) in the neocortex exhibit a high proliferation capacity during early embryonic development and give rise to cortical projection neurons after maturation. Necdin, a mammal-specific MAGE (melanoma antigen) family protein that possesses anti-mitotic and pro-survival activities, is expressed abundantly in postmitotic neurons and moderately in tissue-specific stem cells or progenitors. Necdin interacts with E2F transcription factors and suppresses E2F1-dependent transcriptional activation of the cyclin-dependent kinase Cdk1 gene. Here we show that necdin serves as a suppressor of NPC proliferation in the embryonic neocortex. Necdin is moderately expressed in the ventricular zone of mouse embryonic neocortex, in which proliferative cell populations are significantly increased in necdin-null mice. In the neocortex of necdin-null embryos, expression of Cdk1 and Sox2, a stem cell marker, is significantly increased, whereas expression of p16, a cyclin-dependent kinase inhibitor, is markedly diminished. Cdk1 and p16 expression levels are also significantly increased and decreased, respectively, in primary NPCs prepared from necdin-null embryos. Intriguingly, necdin interacts directly with Bmi1, a Polycomb group protein that suppresses p16 expression and promotes NPC proliferation. In HEK293A cells transfected with luciferase reporter constructs, necdin relieves Bmi1-dependent repression of p16 promoter activity, whereas Bmi1 counteracts necdin-mediated repression of E2F1-dependent Cdk1 promoter activity. In lentivirus-infected primary NPCs, necdin overexpression increases p16 expression, suppresses Cdk1 expression, and inhibits NPC proliferation, whereas Bmi1 overexpression suppresses p16 expression, increases Cdk1 expression, and promotes NPC proliferation. Our data suggest that embryonic NPC proliferation in the neocortex is regulated by the antagonistic interplay between necdin and Bmi1.
|Atheroprotective effect of oleoylethanolamide (OEA) targeting oxidized LDL. |
Fan, A; Wu, X; Wu, H; Li, L; Huang, R; Zhu, Y; Qiu, Y; Fu, J; Ren, J; Zhu, C
PloS one 9 e85337 2014
Dietary fat-derived lipid oleoylethanolamide (OEA) has shown to modulate lipid metabolism through a peroxisome proliferator-activated receptor-alpha (PPAR-α)-mediated mechanism. In our study, we further demonstrated that OEA, as an atheroprotective agent, modulated the atherosclerotic plaques development. In vitro studies showed that OEA antagonized oxidized LDL (ox-LDL)-induced vascular endothelial cell proliferation and vascular smooth muscle cell migration, and suppressed lipopolysaccharide (LPS)-induced LDL modification and inflammation. In vivo studies, atherosclerosis animals were established using balloon-aortic denudation (BAD) rats and ApoE(-/-) mice fed with high-caloric diet (HCD) for 17 or 14 weeks respectively, and atherosclerotic plaques were evaluated by oil red staining. The administration of OEA (5 mg/kg/day, intraperitoneal injection, i.p.) prevented or attenuated the formation of atherosclerotic plaques in HCD-BAD rats or HCD-ApoE(-/-) mice. Gene expression analysis of vessel tissues from these animals showed that OEA induced the mRNA expressions of PPAR-α and downregulated the expression of M-CFS, an atherosclerotic marker, and genes involved in oxidation and inflammation, including iNOS, COX-2, TNF-α and IL-6. Collectively, our results suggested that OEA exerted a pharmacological effect on modulating atherosclerotic plaque formation through the inhibition of LDL modification in vascular system and therefore be a potential candidate for anti-atherosclerosis drug.
|Abelson interactor 1 (ABI1) and its interaction with Wiskott-Aldrich syndrome protein (wasp) are critical for proper eye formation in Xenopus embryos. |
Singh, A; Winterbottom, EF; Ji, YJ; Hwang, YS; Daar, IO
The Journal of biological chemistry 288 14135-46 2013
Abl interactor 1 (Abi1) is a scaffold protein that plays a central role in the regulation of actin cytoskeleton dynamics as a constituent of several key protein complexes, and homozygous loss of this protein leads to embryonic lethality in mice. Because this scaffold protein has been shown in cultured cells to be a critical component of pathways controlling cell migration and actin regulation at cell-cell contacts, we were interested to investigate the in vivo role of Abi1 in morphogenesis during the development of Xenopus embryos. Using morpholino-mediated translation inhibition, we demonstrate that knockdown of Abi1 in the whole embryo, or specifically in eye field progenitor cells, leads to disruption of eye morphogenesis. Moreover, signaling through the Src homology 3 domain of Abi1 is critical for proper movement of retinal progenitor cells into the eye field and their appropriate differentiation, and this process is dependent upon an interaction with the nucleation-promoting factor Wasp (Wiskott-Aldrich syndrome protein). Collectively, our data demonstrate that the Abi1 scaffold protein is an essential regulator of cell movement processes required for normal eye development in Xenopus embryos and specifically requires an Src homology 3 domain-dependent interaction with Wasp to regulate this complex morphogenetic process.
|Degradation of internalized αvβ5 integrin is controlled by uPAR bound uPA: effect on β1 integrin activity and α-SMA stress fiber assembly. |
Wang, L; Pedroja, BS; Meyers, EE; Garcia, AL; Twining, SS; Bernstein, AM
PloS one 7 e33915 2012
Myofibroblasts (Mfs) that persist in a healing wound promote extracellular matrix (ECM) accumulation and excessive tissue contraction. Increased levels of integrin αvβ5 promote the Mf phenotype and other fibrotic markers. Previously we reported that maintaining uPA (urokinase plasminogen activator) bound to its cell-surface receptor, uPAR prevented TGFβ-induced Mf differentiation. We now demonstrate that uPA/uPAR controls integrin β5 protein levels and in turn, the Mf phenotype. When cell-surface uPA was increased, integrin β5 levels were reduced (61%). In contrast, when uPA/uPAR was silenced, integrin β5 total and cell-surface levels were increased (2-4 fold). Integrin β5 accumulation resulted from a significant decrease in β5 ubiquitination leading to a decrease in the degradation rate of internalized β5. uPA-silencing also induced α-SMA stress fiber organization in cells that were seeded on collagen, increased cell area (1.7 fold), and increased integrin β1 binding to the collagen matrix, with reduced activation of β1. Elevated cell-surface integrin β5 was necessary for these changes after uPA-silencing since blocking αvβ5 function reversed these effects. Our data support a novel mechanism by which downregulation of uPA/uPAR results in increased integrin αvβ5 cell-surface protein levels that regulate the activity of β1 integrins, promoting characteristics of the persistent Mf.
|Downregulation of TFPI in breast cancer cells induces tyrosine phosphorylation signaling and increases metastatic growth by stimulating cell motility. |
Stavik, B; Skretting, G; Aasheim, HC; Tinholt, M; Zernichow, L; Sletten, M; Sandset, PM; Iversen, N
BMC cancer 11 357 2011
Increased hemostatic activity is common in many cancer types and often causes additional complications and even death. Circumstantial evidence suggests that tissue factor pathway inhibitor-1 (TFPI) plays a role in cancer development. We recently reported that downregulation of TFPI inhibited apoptosis in a breast cancer cell line. In this study, we investigated the effects of TFPI on self-sustained growth and motility of these cells, and of another invasive breast cancer cell type (MDA-MB-231).Stable cell lines with TFPI (both α and β) and only TFPIβ downregulated were created using RNA interference technology. We investigated the ability of the transduced cells to grow, when seeded at low densities, and to form colonies, along with metastatic characteristics such as adhesion, migration and invasion.Downregulation of TFPI was associated with increased self-sustained cell growth. An increase in cell attachment and spreading was observed to collagen type I, together with elevated levels of integrin α2. Downregulation of TFPI also stimulated migration and invasion of cells, and elevated MMP activity was involved in the increased invasion observed. Surprisingly, equivalent results were observed when TFPIβ was downregulated, revealing a novel function of this isoform in cancer metastasis.Our results suggest an anti-metastatic effect of TFPI and may provide a novel therapeutic approach in cancer.
|Phosphorylation of mixed lineage leukemia 5 by CDC2 affects its cellular distribution and is required for mitotic entry. |
Liu, J; Wang, XN; Cheng, F; Liou, YC; Deng, LW
The Journal of biological chemistry 285 20904-14 2010
The human mixed lineage leukemia-5 (MLL5) gene is frequently deleted in myeloid malignancies. Emerging evidence suggests that MLL5 has important functions in adult hematopoiesis and the chromatin regulatory network, and it participates in regulating the cell cycle machinery. Here, we demonstrate that MLL5 is tightly regulated through phosphorylation on its central domain at the G(2)/M phase of the cell cycle. Upon entry into mitosis, the phosphorylated MLL5 delocalizes from condensed chromosomes, whereas after mitotic exit, MLL5 becomes dephosphorylated and re-associates with the relaxed chromatin. We further identify that the mitotic phosphorylation and subcellular localization of MLL5 are dependent on Cdc2 kinase activity, and Thr-912 is the Cdc2-targeting site. Overexpression of the Cdc2-targeting MLL5 fragment obstructs mitotic entry by competitive inhibition of the phosphorylation of endogenous MLL5. In addition, G(2) phase arrest caused by depletion of endogenous MLL5 can be compensated by exogenously overexpressed full-length MLL5 but not the phosphodomain deletion or MLL5-T912A mutant. Our data provide evidence that MLL5 is a novel cellular target of Cdc2, and the phosphorylation of MLL5 may have an indispensable role in the mitotic progression.Full Text Article
|The N terminus of Cbl-c regulates ubiquitin ligase activity by modulating affinity for the ubiquitin-conjugating enzyme. |
Ryan, PE; Sivadasan-Nair, N; Nau, MM; Nicholas, S; Lipkowitz, S
The Journal of biological chemistry 285 23687-98 2010
Cbl proteins are ubiquitin ligases (E3s) that play a significant role in regulating tyrosine kinase signaling. There are three mammalian family members: Cbl, Cbl-b, and Cbl-c. All have a highly conserved N-terminal tyrosine kinase binding domain, a catalytic RING finger domain, and a C-terminal proline-rich domain that mediates interactions with Src homology 3 (SH3) containing proteins. Although both Cbl and Cbl-b have been studied widely, little is known about Cbl-c. Published reports have demonstrated that the N terminus of Cbl and Cbl-b have an inhibitory effect on their respective E3 activity. However, the mechanism for this inhibition is still unknown. In this study we demonstrate that the N terminus of Cbl-c, like that of Cbl and Cbl-b, inhibits the E3 activity of Cbl-c. Furthermore, we map the region responsible for the inhibition to the EF-hand and SH2 domains. Phosphorylation of a critical tyrosine (Tyr-341) in the linker region of Cbl-c by Src or a phosphomimetic mutation of this tyrosine (Y341E) is sufficient to increase the E3 activity of Cbl-c. We also demonstrate for the first time that phosphorylation of Tyr-341 or the Y341E mutation leads to a decrease in affinity for the ubiquitin-conjugating enzyme (E2), UbcH5b. The decreased affinity of the Y341E mutant Cbl-c for UbcH5b results in a more rapid turnover of bound UbcH5b coincident with the increased E3 activity. These data suggest that the N terminus of Cbl-c contributes to the binding to the E2 and that phosphorylation of Tyr-341 leads to a decrease in affinity and an increase in the E3 activity of Cbl-c.Full Text Article
|Inflammatory corneal (lymph)angiogenesis is blocked by VEGFR-tyrosine kinase inhibitor ZK 261991, resulting in improved graft survival after corneal transplantation. |
Hos, D; Bock, F; Dietrich, T; Onderka, J; Kruse, FE; Thierauch, KH; Cursiefen, C
Investigative ophthalmology & visual science 49 1836-42 2008
To analyze whether tyrosine kinase inhibitors blocking VEGF receptors (PTK787/ZK222584 [PTK/ZK] and ZK261991 [ZK991]) can inhibit not only hemangiogenesis but also lymphangiogenesis and whether treatment with tyrosine kinase inhibitors after corneal transplantation can improve graft survival.Inflammatory corneal neovascularization was induced by corneal suture placement. One treatment group received PTK/ZK, and the other treatment group received ZK991. Corneas were analyzed histomorphometrically for pathologic corneal hemangiogenesis and lymphangiogenesis. The inhibitory effect of tyrosine kinase inhibitors on lymphatic endothelial cells (LECs) in vitro was analyzed with a colorimetric (BrdU) proliferation ELISA. Low-risk allogeneic (C57Bl/6 to BALB/c) corneal transplantations were performed; the treatment group received ZK991, and grafts were graded for rejection (for 8 weeks).Treatment with tyrosine kinase inhibitors resulted in a significant reduction of hemangiogenesis (PTK/ZK by 30%, P less than 0.001; ZK991 by 53%, P less than 0.001) and lymphangiogenesis (PTK/ZK by 70%, P less than 0.001; ZK991 by 71%, P less than 0.001) in vivo. Inhibition of proliferation of LECs in vitro was also significant and dose dependent (PTK/ZK, P less than 0.001; ZK991, P less than 0.001). Comparing the survival proportions after corneal transplantation, treatment with ZK991 significantly improved graft survival (68% vs. 33%; P less than 0.02).Tyrosine kinase inhibitors blocking VEGF receptors are potent inhibitors not only of inflammatory corneal hemangiogenesis but also lymphangiogenesis in vivo. Tyrosine kinase inhibitors seem to have the ability to restrain the formation of the afferent and efferent arm of the immune reflex arc and are therefore able to promote graft survival after corneal transplantation.
|Impaired dendritic cell function in aging leads to defective antitumor immunity. |
Grolleau-Julius, Annabelle, et al.
Cancer Res., 68: 6341-9 (2008) 2008
|IGF-I and insulin activate mitogen-activated protein kinase via the type 1 IGF receptor in mouse embryonic stem cells. |
Nguyen, TT; Sheppard, AM; Kaye, PL; Noakes, PG
Reproduction (Cambridge, England) 134 41-9 2007
Although IGF-I and insulin are important modulators of preimplantation embryonic physiology, the signalling pathways activated during development remain to be elucidated. As a model of preimplantation embryos, pluripotent mouse embryonic stem cells were used to investigate which receptor mediated actions of physiological concentrations of IGF-I and insulin on growth measured by protein synthesis. Exposure of mouse embryonic stem (ES) cells to 1.7 pM IGF-I or 1.7 nM insulin for 4 h caused approximately 25% increase in protein synthesis when compared with cells cultured in basal medium containing BSA. Dose-response studies showed 100-fold higher potency of IGF-I that pointed to the type 1 IGF receptor as the mediating receptor for both ligands. This was confirmed using an anti-type 1 IGF receptor-blocking antibody (alphaIR3). Both 1.7 pM IGF-I and 1.7 nM insulin increased phosphorylation of the type 1 IGF receptor and this increase was blocked by alphaIR3, but the insulin receptor was not phosphorylated. Finally, binding of either agonist led to downstream phosphorylation of ERK1/2 mitogen-activated protein kinase (MAPK) also via IGF-1R as this was blocked by alphaIR3. Together, these results suggest that IGF-I and insulin modulate ES cell physiology through binding to the type 1 IGF receptor and subsequent activation of MAPK pathway.
|Preclinical activity of ABT-869, a multitargeted receptor tyrosine kinase inhibitor. |
Albert, DH; Tapang, P; Magoc, TJ; Pease, LJ; Reuter, DR; Wei, RQ; Li, J; Guo, J; Bousquet, PF; Ghoreishi-Haack, NS; Wang, B; Bukofzer, GT; Wang, YC; Stavropoulos, JA; Hartandi, K; Niquette, AL; Soni, N; Johnson, EF; McCall, JO; Bouska, JJ; Luo, Y; Donawho, CK; Dai, Y; Marcotte, PA; Glaser, KB; Michaelides, MR; Davidsen, SK
Molecular cancer therapeutics 5 995-1006 2006
ABT-869 is a structurally novel, receptor tyrosine kinase (RTK) inhibitor that is a potent inhibitor of members of the vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) receptor families (e.g., KDR IC50 = 4 nmol/L) but has much less activity (IC50s greater than 1 micromol/L) against unrelated RTKs, soluble tyrosine kinases, or serine/threonine kinases. The inhibition profile of ABT-869 is evident in cellular assays of RTK phosphorylation (IC50 = 2, 4, and 7 nmol/L for PDGFR-beta, KDR, and CSF-1R, respectively) and VEGF-stimulated proliferation (IC50 = 0.2 nmol/L for human endothelial cells). ABT-869 is not a general antiproliferative agent because, in most cancer cells, greater than 1,000-fold higher concentrations of ABT-869 are required for inhibition of proliferation. However, ABT-869 exhibits potent antiproliferative and apoptotic effects on cancer cells whose proliferation is dependent on mutant kinases, such as FLT3. In vivo ABT-869 is effective orally in the mechanism-based murine models of VEGF-induced uterine edema (ED50 = 0.5 mg/kg) and corneal angiogenesis (greater than 50% inhibition, 15 mg/kg). In tumor growth studies, ABT-869 exhibits efficacy in human fibrosarcoma and breast, colon, and small cell lung carcinoma xenograft models (ED50 = 1.5-5 mg/kg, twice daily) and is also effective (greater than 50% inhibition) in orthotopic breast and glioma models. Reduction in tumor size and tumor regression was observed in epidermoid carcinoma and leukemia xenograft models, respectively. In combination, ABT-869 produced at least additive effects when given with cytotoxic therapies. Based on pharmacokinetic analysis from tumor growth studies, efficacy correlated more strongly with time over a threshold value (cellular KDR IC50 corrected for plasma protein binding = 0.08 microg/mL, greater than or=7 hours) than with plasma area under the curve or Cmax. These results support clinical assessment of ABT-869 as a therapeutic agent for cancer.
|Colony-stimulating factor-1 (CSF-1) receptor-mediated macrophage differentiation in myeloid cells: a role for tyrosine 559-dependent protein phosphatase 2A (PP2A) activity |
McMahon, K. A., et al
Biochem J, 358:431-6 (2001) 2001
|Immunoblotting (Western), Immunoprecipitation||11513742|
|Increased insulin sensitivity and obesity resistance in mice lacking the protein tyrosine phosphatase-1B gene |
Elchebly, M., et al
Science, 283:1544-8 (1999) 1999
|Altered pattern of TCR/CD3-mediated protein-tyrosyl phosphorylation in T cells from patients with systemic lupus erythematosus. Deficient expression of the T cell receptor zeta chain |
Liossis, S. N., et al
J Clin Invest, 101:1448-57 (1998) 1998
|Replacement of tyrosine 1251 in the carboxyl terminus of the insulin-like growth factor-I receptor disrupts the actin cytoskeleton and inhibits proliferation and anchorage-independent growth. |
Blakesley, V A, et al.
J. Biol. Chem., 273: 18411-22 (1998) 1998
Insulin-like growth factor (IGF)-I signaling through the IGF-I receptor modulates cellular adhesion and proliferation and the transforming ability of cells overexpressing the IGF-I receptor. Tyrosine phosphorylation of intracellular proteins is essential for this transduction of the IGF-I-induced mitogenic and tumorigenic signals. IGF-I induces specific cytoskeletal structure and the phosphorylation of proteins in the associated focal adhesion complexes. The determination of the exact pathways emanating from the IGF-I receptor that are involved in mediating these signals will contribute greatly to the understanding of IGF-I action. We have previously shown that replacement of tyrosine residues 1250 and 1251 in the carboxyl terminus of the IGF-I receptor abrogates IGF-I-induced cellular proliferation and tumor formation in nude mice. In this study, replacement of either tyrosine 1250 or 1251 similarly reduces the cells ability to grow in an anchorage-independent manner. The actin cytoskeleton and cellular localization of vinculin are disrupted by replacement of tyrosine 1251. Tyrosine residues 1250 and 1251 are not essential for tyrosine phosphorylation of two known substrates; insulin receptor substrate-1 and SHC, nor association of known downstream adaptor proteins to these substrates. In addition, these mutant IGF-I receptors do not affect IGF-I-stimulated p42/p44 mitogen-activated protein kinase activation or phosphatidylinositol (PI) 3'-kinase activity. Thus, it appears that in fibroblasts expressing tyrosine 1250 and 1251 mutant IGF-I receptors, the signal transduction pathways impacting on mitogenesis and tumorigenesis do not occur exclusively through the PI 3'-kinase or mitogen-activated protein kinase pathways.
|Compartmentalized activation of the high affinity immunoglobulin E receptor within membrane domains |
Field, K. A., et al
J Biol Chem, 272:4276-80 (1997) 1997
|Interleukin-1 activates a novel protein kinase that phosphorylates the epidermal-growth-factor receptor peptide T669 |
Kracht, M., et al
Biochem J, 302 ( Pt 3):897-905 (1994) 1994
|Oncogenes, growth factors, and signal transduction. |
Druker, B J, et al.
N. Engl. J. Med., 321: 1383-91 (1989) 1989