Immunocytochemical localization of beta II subspecies of protein kinase C in rat brain.

Saito, Naoaki; Kose, Akiko; Ito, Atsuko; Hosoda, Kohkichi; Mori, Miyako; Hirata, Midori; Ogita, Kouji; Kikkawa, Ushio; Ono, Yoshitaka; Igarashi, Koichi

doi:10.1073/pnas.86.9.3409

Cited by 106 publications

(39 citation statements)

References 36 publications

(47 reference statements)

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“…Our finding that PKC␤2 is localized in the Golgi is consistent with previous observations (45)(46)(47). Interestingly, activation of PKC by a phorbol ester (phorbol myristic acid) has been reported to induce PKC␤2 to move from the cytoplasm to the Golgi apparatus (48).…”

Section: Discussionsupporting

confidence: 93%

Protein Kinase C β2-Dependent Phosphorylation of Core 2 GlcNAc-T Promotes Leukocyte-Endothelial Cell Adhesion

et al. 2003

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Increased leukocyte-endothelial cell adhesion is a key early event in the development of retinopathy and atherogenesis in diabetic patients. We recently reported that raised activity of glycosylating enzyme [␤]1,6 acetylglucosaminyltransferase (core 2 GlcNAc-T) is responsible for increased leukocyte-endothelial cell adhesion and capillary occlusion in retinopathy. Here, we demonstrate that elevated glucose increases the activity of core 2 GlcNAc-T and adhesion of human leukocytes to retinal capillary endothelial cells, in a dose-dependent manner, through diabetes-activated serine/threonine protein kinase C ␤2 (PKC␤2)-dependent phosphorylation. This regulatory mechanism, involving phosphorylation of core 2 GlcNAc-T, is also present in polymorphonuclear leukocytes isolated from type 1 and type 2 diabetic patients. Inhibition of PKC␤2 activation with the specific inhibitor, LY379196, attenuated serine phosphorylation of core 2 GlcNAc-T and prevented increased leukocyte-endothelial cell adhesion. Raised activity of core 2 GlcNAc-T was associated with a threefold increase in O-linked glycosylation of P-selectin glycoprotein ligand-1 on the surface of leukocytes of diabetic patients compared with age-matched control subjects. PKC␤2-dependent phosphorylation of core 2 GlcNAc-T may thus represent a novel regulatory mechanism for activation of this key enzyme in mediating increased leukocyte-endothelial cell adhesion and capillary occlusion in diabetic retinopathy. Diabetes 52: 1519 -1527, 2003 D iabetic retinopathy, a leading cause of severe visual loss in type 1 and type 2 diabetic patients (1) is characterized in its early stage by areas of capillary nonperfusion and microvascular damage (2,3). As in atherogenesis (4), increased leukocyteendothelial cell adhesion is a key early event in the development of capillary occlusion in retinopathy (5-10). Leukocytes from diabetic patients are more adhesive to endothelial cells (11), and in experimental diabetes, their increased entrapment in retinal capillaries leads to areas of capillary nonperfusion and endothelial cell damage (12). Increased adhesion of leukocytes in diabetic patients may result from an increased expression of intracellular adhesion molecule (ICAM)-1 on endothelial cells and/or expression of integrins (CD11a, CD11b, and CD18b) on leukocytes (13-16).We recently reported that raised activity of the glycosylating enzyme [␤]1,6-acetylglucosaminyltransferase (core 2 GlcNAc-T) is responsible for increased leukocyte-endothelial cell adhesion and capillary occlusion in retinopathy (17). This Golgi enzyme plays a crucial role in the biosynthesis of O-linked glycans by converting core 1 (i.e., Gal (21), T-cell activation (22), inflammation (23), myocardial dysfunction (24,25), capillary morphogenesis (26), and myeloblastic leukemia (27). On the basis that O-linked sugars are also involved in cell-cell interactions (28), we proposed that their modification by raised activity of core 2 GlcNAc-T, together with glucose-induced expression of adhesion molecules on endoth...

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Section: Discussionsupporting

confidence: 93%

Protein Kinase C β2-Dependent Phosphorylation of Core 2 GlcNAc-T Promotes Leukocyte-Endothelial Cell Adhesion

et al. 2003

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“…The finding that PKC PII is not located in the nucleus of these cells accords with the observation of Saito et al (1989).…”

Section: Pkc Isozymes In Subcellular Fractionssupporting

confidence: 89%

Differential nuclear localization of protein kinase C isoforms in neuroblastoma × glioma hybrid cells

Beckmann

Lindschau

Haller

et al. 1994

European Journal of Biochemistry

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The protein kinase C (PKC) a, p and E isoforms have distinct nuclear localizations in neuroblastoma X glioma hybrid cells NG 108-15. We found by immunoblotting that PKC a, pII, 6 and E are the predominant isoforms in these cells. In contrast to other neuronal cell lines, none of these isoforms is down-regulated during differentiation.Confocal immunofluorescence microscopy revealed that in undifferentiated cells PKC a is located in the cytoplasm and in the nucleus excluding nucleoli. In differentiated cells PKC a was almost exclusively located in the cytoplasm. Stimulation of the cells with phorbol ester resulted in translocation to the plasma membrane. PKC PII was not detectable in the nuclei. PKC 6 was found in the nucleoli and in the cytoplasm, in differentiated cells particularly in the neurites. Phorbol ester failed to induce a translocation to other compartments. PKC E was localized with the nuclear-pore complexes at the nuclear envelope. In differentiated cells after stimulation with phorbol ester, partial translocation to the plasma membrane was observed.Protein kinase C (PKC) plays a key role in many signaltransduction pathways and cellular processes (for review see Nishizuka, 1986;Lester and Epand, 1992). Ten isoforms of PKC are found in mammals, showing characteristic patterns of expression in different tissues. Four isoforms (called PKC A forms), PKC a, PI, pII and 7, are phospholipid and Ca2+ dependent in contrast to the B forms such as PKC 6, E and cwhich are Ca2+ independent (Stabel and Parker, 1991). After an increase of intracellular Ca2+ levels the PKC A isoforms were shown to be translocated to the plasma membrane. Binding to the plasma membrane via phospholipids enables activation by the second messenger diacylglycerol (Huang, 1989).There is evidence that members of the PKC family respond differently to various combinations of Caz+ and phospholipid-degradation products. This could be one of the reasons for distinct intracellular distribution and activation patterns (Asaoka et al., 1992).Several investigators have observed translocation to other cell compartments including the cell nucleus in addition to the plasma membrane. With fibroblast cells, Leach et al. (1992) observed translocation of PKC a to the cell nucleus after treatment with phorbol ester or a-thrombin. In promyelocytic leukemia (HL 60) cells, stimulation with the PKC activator bryostatin leads to a selective translocation of PKC P but not PKC a to the nucleus (Hocevar and Fields, 1991).In liver, PKC BI1 was found in the nuclei (Rogue et al., 1990 found PKC a and PKC y as the 'membrane inserted' and constitutively active form.The current view is that each cell type expresses a specific set of PKC isoforms, which are localized and regulated in a cell-specific manner. It is not yet understood how this differential expression, localization, and regulation is achieved. The specific localizations of PKC isoforms imply specific functions for each cell type. Due to the known effects of PKC activation on nuclear events (induction of proli...

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“…After washing with TBS containing 0.1% Tween 20, the membrane was incubated with specific antibodies for 8 different PKC isoforms for 2 h at room temperature. Anti-a, -bI, -g, -d, -e, -z and -h PKC polyclonal antibodies were purchased from Oxford Biomedical Research (Oxford, MI, USA), and the anti-b II polyclonal antibody was prepared as described in the previous report (19). The membrane was then washed and incubated for 1 h with peroxidase-conjugated goat antirabbit immunoglobulin.…”

Section: Western Blot Analysis Of Pkc Translocationmentioning

confidence: 99%

Molecular Mechanisms for α2-Adrenoceptor-Mediated Regulation of Synoviocyte Populations

Mishima

Otani

Tanabe

et al. 2001

Japanese Journal of Pharmacology

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ABSTRACT-The sympathetic nervous system has been indicated to influence the severity of inflammatory disease including rheumatoid arthritis. In this study, we elucidated the effects of catecholamine on the synovial cell populations. Stimulation with epinephrine or norepinephrine for 1 -2 weeks dose-and time-dependently increased the number of synovial A (macrophage-like) cells but decreased that of B (fibroblast-like) cells. These responses in A and B cells were inhibited by the a 2-antagonist yohimbine, the G-protein inactivator pertussis toxin and the phospholipase C (PLC) inhibitor U-73122. Furthermore, the protein kinase C (PKC) inhibitor calphostin C and mitogen-activated protein (MAP) kinase inhibitors PD98059 and wortmannin also abolished the norepinephrine effects on A and B cell numbers. In A cells cloned from an A and B cell mixture, norepinephrine also increased the cell number. In immunoblotting and immunocytostaining analyses, among the PKC isozymes, only PKC b II immunoreactivity was observed in the cytoplasm of unstimulated A and B cells. After a 2-adrenoceptor stimulation, PKC b II immunoreactivity increased in the plasma membranes of both A and B cells with decreases in the cytoplasm. These findings indicated that a 2-adrenoceptor stimulation of type A and B synoviocytes produced an increase and a decrease in the respective cell number, probably through Gi-coupled PLC activation and the resulting stimulation of the PKC bII /MAP kinase.

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Immunocytochemical localization of beta II subspecies of protein kinase C in rat brain.

Cited by 106 publications

References 36 publications

Protein Kinase C β2-Dependent Phosphorylation of Core 2 GlcNAc-T Promotes Leukocyte-Endothelial Cell Adhesion

Protein Kinase C β2-Dependent Phosphorylation of Core 2 GlcNAc-T Promotes Leukocyte-Endothelial Cell Adhesion

Differential nuclear localization of protein kinase C isoforms in neuroblastoma × glioma hybrid cells

Molecular Mechanisms for α2-Adrenoceptor-Mediated Regulation of Synoviocyte Populations

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