Casein Kinase 1 Regulates Connexin-43 Gap Junction Assembly

Cooper, Cynthia D.; Lampe, Paul D.

doi:10.1074/jbc.m209427200

Cited by 183 publications

(176 citation statements)

References 45 publications

Supporting

Mentioning

169

Contrasting

Order By: Relevance

“…4). In addition, previous work from our lab has shown that Casein Kinase 1 is important for plaque formation, as inhibition of CK1 led to a decrease in gap junction plaques and an increase in hemichannels in the plasma membrane (Cooper & Lampe, 2002). Taken together, these data are consistent with the idea that phosphorylation on some combination of S325/328/330 by CK1 results in a conformational change resulting in the P2 isoform and inclusion in a gap junction plaque.…”

Section: Inclusion In the Gap Junction Plaque And Formation Of P2supporting

confidence: 88%

“…Consistent with Musil and Goodenough (1991), the P2 isoform was insoluble after extraction of cells with Triton X-100 as indicated in the middle lane (Ab: Total, Prep: Tx Ins) of Fig 1A. When that same lane is simultaneously probed with an antibody (pS325) that is specific for Cx43 when it is phosphorylated at S325, S328 and/or S330, we found that only the P2 isoform was present (third lane, Ab:pS325, Prep:Tx Ins). We had previously shown that this phosphospecific antibody labeled the intercalated disk region of cardiomyocytes (Lampe et al, 2006) and that S325/328/330 phosphorylation was important in gap junction assembly (Cooper & Lampe, 2002). In Fig.…”

Section: Formation Of the P2 Isoformmentioning

confidence: 83%

See 1 more Smart Citation

Key Connexin 43 Phosphorylation Events Regulate the Gap Junction Life Cycle

2007

Self Cite

View full text Add to dashboard Cite

Connexin43 (Cx43), the most widely expressed and abundant vertebrate gap junction protein, is phosphorylated at multiple different serine residues during its life cycle. Cx43 is phosphorylated soon after synthesis and phosphorylation changes as it traffics through the endoplasmic reticulum and Golgi to the plasma membrane ultimately forming into a gap junction structure. The electrophoretic mobility of Cx43 changes as the protein proceeds through its life cycle with prominent bands often labeled P0, P1 and P2. Many reports have indicated changes in "phosphorylation" based on these mobility shifts and others that occur in response to growth factors or other biological effectors. Here we indicate how phosphospecific and epitope specific antibodies can be utilized to show when and where certain phosphorylation events occur during the Cx43 life cycle. These reagents show that phosphorylation at S364 and or S365 is involved in forming the P1 isoform, an event that apparently regulates trafficking to or within the plasma membrane. Phosphorylation at S325, 328, and/or 330 is necessary to form a P2 isoform and this phosphorylation event is present only in gap junctions. Treatment with protein kinase C activators led to phosphorylation at S368, S279/S282 and S262 with a shift in mobility in CHO cells but not MDCK cells. The shift was dependent on MAPK activity but not phosphorylation at S279/282. However, phosphorylation at S262 could explain the shift. By defining these phosphorylation events, we have begun to be able to sort out the critical signaling pathways that regulate gap junction function.

show abstract

Section: Inclusion In the Gap Junction Plaque And Formation Of P2supporting

confidence: 88%

Section: Formation Of the P2 Isoformmentioning

confidence: 83%

Key Connexin 43 Phosphorylation Events Regulate the Gap Junction Life Cycle

2007

Self Cite

View full text Add to dashboard Cite

show abstract

“…As illustrated in Figure 4c, after 6-8 h of incubation with IC261 (see also Materials and methods; Cooper and Lampe (2002) and Li et al (2004)), the signal intensity of nm23 phosphorylation decreased by 65% (quantified by imaging scan analyses; data not shown). To confirm any effects of inhibition of CKI on nm23 phosphorylation in cells and to avoid any misinterpretation relating to the relatively high levels of IC261 used (see below), here we also treated the MDA-MB-H1-177 cells with the two additional CKI inhibitors indicated above: D4476 and CKI-7 (Figure 4d).…”

Section: Resultsmentioning

confidence: 92%

“…In these assays, IC261 was used at a concentration of 50 mM, CKI-7 at 400 mM, and D4476 at 25 mM, according to the concentrations reported in the literature (Cooper and Lampe, 2002;Izeradjene et al, 2004;Li et al, 2004;Rena et al, 2004).…”

Section: Resultsmentioning

confidence: 99%

Phosphorylation of nm23-H1 by CKI induces its complex formation with h-prune and promotes cell motility

Garzia¹,

D’Angelo²,

Amoresano

et al. 2007

Oncogene

View full text Add to dashboard Cite

The combination of an increase in the cAMP-phosphodiesterase activity of h-prune and its interaction with nm23-H1 have been shown to be key steps in the induction of cellular motility in breast cancer cells. Here we present the molecular mechanisms of this interaction. The region of the nm23-h-prune interaction lies between S120 and S125 of nm23, where missense mutants show impaired binding; this region has been highly conserved throughout evolution, and can undergo serine phosphorylation by casein kinase I. Thus, the casein kinase I d-e specific inhibitor IC261 impairs the formation of the nm23-hprune complex, which translates 'in vitro' into inhibition of cellular motility in a breast cancer cellular model. A competitive permeable peptide containing the region for phosphorylation by casein kinase I impairs cellular motility to the same extent as IC261. The identification of these two modes of inhibition of formation of the nm23-H1-h-prune protein complex pave the way toward new challenges, including translational studies using IC261 or this competitive peptide 'in vivo' to inhibit cellular motility induced by nm23-H1-h-prune complex formation during progression of breast cancer.

show abstract

“…Similarly, our results with the p38 MAPK inhibitor SB202190 indicate that the MAPK pathway is responsible, in part, for the inhibitory effects of S. aureus on functional GJC in astrocytes. However, the participation of other kinases that have been shown to interact with Cx43, such as PKC (Martinez et al, 2002;Reynhout et al, 1992), casein kinase 1 (Cooper and Lampe, 2002), PKA (Burghardt et al, 1995;TenBroek et al, 2001), and c-Src Sorgen et al, 2004) cannot be excluded in modulating the S. aureus-induced decrease in Cx43 expression, and warrant further investigation.…”

Section: Discussionmentioning

confidence: 99%

Modulation of connexin expression and gap junction communication in astrocytes by the gram‐positive bacterium S. aureus

Esen

Shuffield

Syed

et al. 2006

Glia

View full text Add to dashboard Cite

Gap junctions establish direct intercellular conduits between adjacent cells and are formed by the hexameric organization of protein subunits called connexins (Cx). It is unknown whether the proinflammatory milieu that ensues during CNS infection with S. aureus, one of the main etiologic agents of brain abscess in humans, is capable of eliciting regional changes in astrocyte homocellular gap junction communication (GJC) and, by extension, influencing neuron homeostasis at sites distant from the primary focus of infection. Here we investigated the effects of S. aureus and its cell wall product peptidoglycan (PGN) on Cx43, Cx30, and Cx26 expression, the main Cx isoforms found in astrocytes. Both bacterial stimuli led to a time-dependent decrease in Cx43 and Cx30 expression; however, Cx26 levels were elevated following bacterial exposure. Functional examination of dye coupling, as revealed by single-cell microinjections of Lucifer yellow, demonstrated that both S. aureus and PGN inhibited astrocyte GJC. Inhibition of protein synthesis with cyclohexamide (CHX) revealed that S. aureus directly modulates, in part, Cx43 and Cx30 expression, whereas Cx26 levels appear to be regulated by a factor(s) that requires de novo protein production; however, CHX did not alter the inhibitory effects of S. aureus on astrocyte GJC. The p38 MAPK inhibitor SB202190 was capable of partially restoring the S. aureus-mediated decrease in astrocyte GJC to that of unstimulated cells, suggesting the involvement of p38 MAPK-dependent pathway(s). These findings could have important implications for limiting the long-term detrimental effects of abscess formation in the brain which may include seizures and cognitive deficits.

show abstract

Casein Kinase 1 Regulates Connexin-43 Gap Junction Assembly

Cited by 183 publications

References 45 publications

Key Connexin 43 Phosphorylation Events Regulate the Gap Junction Life Cycle

Key Connexin 43 Phosphorylation Events Regulate the Gap Junction Life Cycle

Phosphorylation of nm23-H1 by CKI induces its complex formation with h-prune and promotes cell motility

Modulation of connexin expression and gap junction communication in astrocytes by the gram‐positive bacterium S. aureus

Contact Info

Product

Resources

About