Search results for "Protein Kinase C-alpha"
showing 7 items of 7 documents
Phosphorylation of meprin β controls its cell surface abundance and subsequently diminishes ectodomain shedding
2021
Meprin β is a zinc-dependent metalloprotease exhibiting a unique cleavage specificity with strong preference for acidic amino acids at the cleavage site. Proteomic studies revealed a diverse substrate pool of meprin β including the interleukin-6 receptor (IL-6R) and the amyloid precursor protein (APP). Dysregulation of meprin β is often associated with pathological conditions such as chronic inflammation, fibrosis, or Alzheimer's disease (AD). The extracellular regulation of meprin β including interactors, sheddases, and activators has been intensively investigated while intracellular regulation has been barely addressed in the literature. This study aimed to analyze C-terminal phosphorylat…
Interaction of Mitogen-activated Protein Kinases with the Kinase Interaction Motif of the Tyrosine Phosphatase PTP-SL Provides Substrate Specificity …
1999
ERK1 and ERK2 associate with the tyrosine phosphatase PTP-SL through a kinase interaction motif (KIM) located in the juxtamembrane region of PTP-SL. A glutathione S-transferase (GST)-PTP-SL fusion protein containing the KIM associated with ERK1 and ERK2 as well as with p38/HOG, but not with the related JNK1 kinase or with protein kinase A or C. Accordingly, ERK2 showed in vitro substrate specificity to phosphorylate GST-PTP-SL in comparison with GST-c-Jun. Furthermore, tyrosine dephosphorylation of ERK2 by the PTP-SLDeltaKIM mutant was impaired. The in vitro association of ERK1/2 with GST-PTP-SL was highly stable; however, low concentrations of nucleotides partially dissociated the ERK1/2.P…
Clustering induces a lateral redistribution of α2β1 integrin from membrane rafts to caveolae and subsequent protein kinase C-dependent internalization
2004
Integrin alpha 2 beta 1 mediates the binding of several epithelial and mesenchymal cell types to collagen. The composition of the surrounding plasma membrane, especially caveolin-1- and cholesterol-containing membrane structures called caveolae, may be important to integrin signaling. On cell surface alpha 2 beta 1 integrin was located in the raft like membrane domain, rich in GPI-anchored proteins, rather than in caveolae. However, when antibodies were used to generate clusters of alpha 2 beta 1 integrin, they started to move laterally on cell surface along actin filaments. During the lateral movement small clusters fused together. Finally alpha 2 beta 1 integrin was found inside caveolae …
Cell Susceptibility to Baculovirus Transduction and Echovirus Infection Is Modified by Protein Kinase C Phosphorylation and Vimentin Organization
2013
ABSTRACT Some cell types are more susceptible to viral gene transfer or virus infection than others, irrespective of the number of viral receptors or virus binding efficacy on their surfaces. In order to characterize the cell-line-specific features contributing to efficient virus entry, we studied two cell lines (Ea.hy926 and MG-63) that are nearly nonpermissive to insect-specific baculovirus (BV) and the human enterovirus echovirus 1 (EV1) and compared their characteristics with those of a highly permissive (HepG2) cell line. All the cell lines contained high levels of viral receptors on their surfaces, and virus binding was shown to be efficient. However, in nonpermissive cells, BV and it…
Differential roles of PKCα and PKCɛ in controlling the gene expression of Nox4 in human endothelial cells
2007
NADPH oxidases are major sources of superoxide in the vascular wall. This study investigates the role of protein kinase C (PKC) in regulating gene expression of NADPH oxidases. Treatment of human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 endothelial cells with phorbol 12-myristate 13-acetate (PMA) or phorbol 12,13-dibutyrate led to a PKC-dependent biphasic expression of the gp91phox homolog Nox4. A downregulation of Nox4 was observed at 6 h and an upregulation at 48 h after phorbol ester treatment. The early Nox4 downregulation was associated with a reduced superoxide production, whereas the late Nox4 upregulation was accompanied by a clear enhancement of superoxi…
Activation of protein kinase C alpha and/or epsilon enhances transcription of the human endothelial nitric oxide synthase gene.
1998
In primary human umbilical vein endothelial cells (HUVECs), incubation with phorbol-12-myristate-13-acetate (PMA) enhanced basal and bradykinin-stimulated nitric oxide production. In the HUVEC-derived cell line EA.hy 926, PMA and phorbol-12,13-dibutyrate stimulated endothelial nitric oxide synthase (NOS III) mRNA expression in a concentration- and time-dependent manner. Maximal mRNA expression (3.3-fold increase) was observed after 18 hr. NOS III protein and activity were increased to a similar extent. The specific protein kinase C (PKC) inhibitors bisindolylmaleimide I (1 microM), Gö 6976 [12-(2 cyanoethyl)-6,7,12, 13-tetrahydro-13-methyl-5-oxo-5H-indolo[2,3-a]pyrrolo-[3, 4-c]carbazole] (1…
Protein kinase C promotes angiogenic activity of human endothelial cells via induction of vascular endothelial growth factor
2008
Aims Protein kinase C (PKC) plays an important role in the regulation of angiogenesis. However, downstream targets of PKC in endothelial cells are poorly defined. Methods and results mRNA expression of vascular endothelial growth factor (VEGF) was analysed by quantitative real-time RT-PCR in human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 cells. siRNA was used to knockdown PKC isoforms and VEGF. Matrigel tube formation assay was used to analyse the angiogenic activity of endothelial cells. Phorbol-12-myristate-13-acetate (PMA) enhanced the ability of HUVEC to organize into tubular networks when plated on Matrigel, a phenomenon that could be prevented by PKC inhibi…