Induction of neurites by the regulatory domains of PKCδ and ε is counteracted by PKC catalytic activity and by the RhoA pathway

Ling, Mia; Troller, A. Ulrika; Zeidman, Ruth; Lundberg, Cecilia; Larsson, Christer

doi:10.1016/j.yexcr.2003.08.013

Cited by 36 publications

(39 citation statements)

References 49 publications

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“…RD cells were transiently transfected using cDNA constructs encoding EGFP-tagged full-length PKC isoforms ␣, ␦, and ⑀ (PKC␣FL-E, PKC␦FL-E, PKC⑀FL-E, respectively); EGFP-tagged PKC⑀ catalytic domain (PKC⑀CD-E) or regulatory domain (PKC⑀RD-E) (36); myc-tagged PSC1V3 subdomains (PKC⑀PSC1V3-myc) (37) and C2 subdomains (PKC⑀C2-myc) generated by inserting the BglII/SalI fragment from PKC⑀C2-EGFP (36) in BamHI/XhoI-digested pcDNA4-myc-His plasmid (Invitrogen); EGFP-tagged myristoylated full-length PKC␣ (Myr-PKC␣-E) or PKC⑀ (Myr PKC⑀-E) (38); GFP-tagged, full-length PKC⑀ (GFP-PKC⑀FL); or kinase-inactive PKC⑀ mutants K552M (GFP-PKC⑀FL-K/M) or K438R (PKC⑀FLKD-E) (39). We found that both of these kinase-inactive PKC⑀ mutants gave similar results, so for simplicity we used PKC⑀-KD to refer to these constructs.…”

Section: Methodsmentioning

confidence: 99%

Regulation of ADAM12 Cell-surface Expression by Protein Kinase C ϵ

Sundberg

Thodeti

Kveiborg

et al. 2004

Journal of Biological Chemistry

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The ADAM (a disintegrin and metalloprotease) family consists of multidomain cell-surface proteins that have a major impact on cell behavior. These transmembraneanchored proteins are synthesized as proforms that have (from the N terminus): a prodomain; a metalloprotease-, disintegrin-like-, cysteine-rich, epidermal growth factor-like, and transmembrane domain; and a cytoplasmic tail. The 90-kDa mature form of human ADAM12 is generated in the trans-Golgi through cleavage of the prodomain by a furin-peptidase and is stored intracellularly until translocation to the cell surface as a constitutively active protein. However, little is known about the regulation of ADAM12 cell-surface translocation. Here, we used human RD rhabdomyosarcoma cells, which express ADAM12 at the cell surface, in a temporal pattern. We report that protein kinase C (PKC) ⑀ induces ADAM12 translocation to the cell surface and that catalytic activity of PKC⑀ is required for this translocation. Cells possess a diverse array of surface proteins, lipids, and carbohydrates that provide active gateways for the selective intake and release of molecular information, which is important in regulating cell behavior. In fact, many disease processes relate to disorganized cell-surface communication systems. ADAMs 1 belong to a large family of cell-surface proteins with over 30 members. The prototypical ADAM molecule is a transmembrane glycoprotein composed of several distinct domains, including a prodomain and a metalloprotease, disintegrin-like, cysteine-rich, epidermal growth factor-like, transmembrane, and cytoplasmic domain. ADAMs play important roles in cell adhesion, interacting with integrins and syndecans, and in the proteolysis of the ectodomains of cell-surface proteins,

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Section: Methodsmentioning

confidence: 99%

Regulation of ADAM12 Cell-surface Expression by Protein Kinase C ϵ

Sundberg

Thodeti

Kveiborg

et al. 2004

Journal of Biological Chemistry

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“…Moreover, it has been described that the regulatory domain of PKC␦ inhibits RhoA by an unknown mechanism and decreases the level of stress fibers in neuronal cells (Ling et al, 2004). Cdc42, and to a lesser extent Rac, are important downstream factors in the pathway through which PKC might mediate morphological and cytoskeletal effects, including stress fibers loss (Troller and Larsson, 2006).…”

Section: Molecular Machinery Involved In the Formation Of The Actin Cmentioning

confidence: 99%

“…Yellow fluorescent protein (YFP)-actin and GFP-tagged plasmids were from Clontech (Palo Alto, CA). GFP-WA and GFP-WASP⌬WA, myc RhoB wt, pSUPER RhoB, GFP-PKC␦ (Ling et al, 2004), and flag cortactin (Weed et al, 2000) were kindly provided by M. Way (London Research Institute, London, United Kingdom), A. J. Ridley (Ludwig Institute for Cancer Research and Department of Biochemistry and Molecular Biology, University College London, London, United Kingdom), C. Larsson (Lund University, Lund, Sweden), and S. A. Weed (West Virginia University, Morgantown, WV), respectively. …”

mentioning

confidence: 99%

Protein Kinase Cδ and Calmodulin Regulate Epidermal Growth Factor Receptor Recycling from Early Endosomes through Arp2/3 Complex and Cortactin

Lladó

Timpson

Muga

et al. 2008

MBoC

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The intracellular trafficking of the epidermal growth factor receptor (EGFR) is regulated by a cross-talk between calmodulin (CaM) and protein kinase C␦ (PKC␦). On inhibition of CaM, PKC␦ promotes the formation of enlarged early endosomes and blocks EGFR recycling and degradation. Here, we show that PKC␦ impairs EGFR trafficking due to the formation of an F-actin coat surrounding early endosomes. The PKC␦-induced polymerization of actin is orchestrated by the Arp2/3 complex and requires the interaction of cortactin with PKC␦. Accordingly, inhibition of actin polymerization by using cytochalasin D or by overexpression of active cofilin, restored the normal morphology of the organelle and the recycling of EGFR. Similar results were obtained after down-regulation of cortactin and the sequestration of the Arp2/3 complex. Furthermore we demonstrate an interaction of cortactin with CaM and PKC␦, the latter being dependent on CaM inhibition. In summary, this study provides the first evidence that CaM and PKC␦ organize actin dynamics in the early endosomal compartment, thereby regulating the intracellular trafficking of EGFR. INTRODUCTIONCalmodulin (CaM) is a ubiquitous small calcium sensor that regulates a variety of cellular processes in a spatial and temporal manner within the cell (Toutenhoofd and Strehler, 2000). Microenvironment variations in the concentration of CaM may be critical to the control of cellular processes that involve specific and high-affinity CaM-binding proteins (Berridge et al., 2000;Carafoli, 2002;Kahl and Means, 2003).We have previously shown that CaM is crucial to the regulation of the dynamics of endosomes. In particular, in the presence of W13, a highly specific CaM antagonist, trafficking is blocked in early endosomes, thereby interfering with transport toward degradation and recycling pathways. This blockage was associated with a dramatic alteration of the morphology and size of early endosomes (Tebar et al., 2002;Lladó et al., 2004). Furthermore we showed that a cross-talk between CaM and protein kinase C␦ (PKC␦) is involved in the regulation of the budding from the early endocytic compartment (Lladó et al., 2004).Several lines of evidence implicate the actin cytoskeleton in the CaM-and PKC␦-mediated regulation of vesicular trafficking. Because actin contributes to the maintenance of organelle stability (Apodaca, 2001), swelling and morphological changes observed in response to CaM/PKC␦ activity (Lladó et al., 2004) may involve altered actin dynamics. Moreover, several CaM-binding proteins and PKC␦ substrates are also actin-binding proteins, including ␣-actinin, adducin, and myristoylated alanine-rich protein kinase C substrate (MARCKS) (Chakravarthy et al., 1999). Finally, RhoGTPases and CaM-binding proteins responsible for fusion-fission events during vesicular trafficking also depend on actin filaments for pinch-off and vesicular movement (Mayorga et al., 1994;Mu et al., 1995;Colombo et al., 1997;Ridley, 2001;Burgoyne and Clague, 2003;Lawe et al., 2003;Donaldson, 2005).The actin cytosk...

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“…PKC⑀ specifically regulates receptor trafficking and extracellular signal-regulated kinase signaling in hepatocyte growth factor/c-Met-induced cell migration (45). In neuroblastoma cells, PKC⑀ can promote neurite outgrowth through interactions of its regulatory domain (46). Rac activation may also be mediated by Ca 2ϩ and by phosphorylation of RhoGDI by conventional PKC (47).…”

Section: Iqgap1mentioning

confidence: 99%

IQGAP1 Promotes Neurite Outgrowth in a Phosphorylation-dependent Manner

McNulty

Marler

et al. 2005

Journal of Biological Chemistry

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In eukaryotic cells IQGAP1 binds to and alters the function of several proteins, including actin, E-cadherin, ␤-catenin, Cdc42, and Rac1. Yeast IQGAP1 homologues have an important role in cytoskeletal organization, suggesting that modulation of the cytoskeleton is a fundamental role of IQGAP1. Phosphorylation is a common mechanism by which cells regulate protein function. Here we demonstrate that endogenous IQGAP1 is highly phosphorylated in MCF-7 human breast epithelial cells. Moreover, incubation of cells with phorbol 12-myristate 13-acetate (PMA) stimulated phosphate incorporation into IQGAP1. By using mass spectrometry, Ser-1443 was identified as the major site phosphorylated on IQGAP1 in intact cells treated with PMA. Ser-1441 was also phosphorylated but to a lesser extent. In vitro analysis with purified proteins documented that IQGAP1 is a substrate for protein kinase C⑀, which catalyzes phosphorylation on Ser-1443. Consistent with these findings, inhibition of cellular protein kinase C via bisindolymaleimide abrogated Ser-1443 phosphorylation in response to PMA. To elucidate the biological sequelae of phosphorylation, Ser-1441 and Ser-1443 were converted either to alanine, to create a nonphosphorylatable construct, or to glutamic acid and aspartic acid, respectively, to generate a phosphomimetic IQGAP1. Although overexpression of wild type IQGAP1 promoted neurite outgrowth in N1E-115 neuroblastoma cells, the nonphosphorylatable IQGAP1 S1441A/S1443A had no effect. In contrast, the S1441E/S1443D mutation markedly enhanced the ability of IQGAP1 to induce neurite outgrowth. Our data disclose that IQGAP1 is phosphorylated at multiple sites in intact cells and that phosphorylation of IQGAP1 will alter its ability to regulate the cytoskeleton of neuronal cells.Initially identified 10 years ago, IQGAP1 has been shown to participate in several fundamental cellular processes (for reviews see Refs 1 and 2). These include cell-cell attachment, ␤-catenin-mediated transcription, cell migration, regulation of actin, microtubule function, the mitogen-activated protein kinase cascade, and Ca 2ϩ /calmodulin signaling (2-4). IQGAP1 is a component of these diverse functions via direct interactions with multiple target proteins that are mediated by a number of protein interaction motifs in IQGAP1. These include the following: a calponin homology domain, responsible for actin binding (5, 6); a WW motif, which is necessary for the association of extracellular signal-regulated kinase 2 (a component of the mitogen-activated protein kinase pathway) (4); a calmodulinbinding IQ domain (5, 7); and a RasGAP-related domain that binds the small GTPases Cdc42 and Rac1 (5, 8). In addition, IQGAP1 binds to and regulates the functions of E-cadherin, ␤-catenin, and CLIP-170 (9 -12).Accumulating evidence reveals an important role for IQGAP1 in cytoskeletal function. The cytoskeleton of eukaryotic cells comprises several elements, including actin, microtubules, and intermediate filaments. Numerous proteins interact with the actin cytoskeleton...

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Induction of neurites by the regulatory domains of PKCδ and ε is counteracted by PKC catalytic activity and by the RhoA pathway

Cited by 36 publications

References 49 publications

Regulation of ADAM12 Cell-surface Expression by Protein Kinase C ϵ

Regulation of ADAM12 Cell-surface Expression by Protein Kinase C ϵ

Protein Kinase Cδ and Calmodulin Regulate Epidermal Growth Factor Receptor Recycling from Early Endosomes through Arp2/3 Complex and Cortactin

IQGAP1 Promotes Neurite Outgrowth in a Phosphorylation-dependent Manner

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