Ceramide-activated protein phosphatases

Purification and characterization of ceramide-activated protein phosphatases. Biochemistry 37 11232-11238. 

Nickels, J.T. and Broach, J.R., 1996, A ceramide-activated protein phosphatase mediates ceramide-induced G1 arrest of Saccharomyces cerevisiae. Genes Dev. 10 382-394. 

Reyes, J.G, Robayna, LG, Delgado, P.S, Gonzalez, I.H, Aguiar, J.Q, Rosas, F.E, Banjul, L.F, and Galarreta, C.M., 1996, c-Jun is a downstream target for ceramide-activated protein phosphatase in A431 ceUs. J. Biol. Chem. 271 21375-21380. 

Salinas, M., Lopez-ValdaUso, R., Martin, D., Alvarez, A., and Cuadrado, A., 2000, Inhibition ofPKB/Aktl by C2-ceramide involves activation of ceramide-activated protein phosphatase in PCI2 ceUs. MoZ. Cell. Neurosci. 15 156-169. 

Wolff, R.A., Dobrowsky, R.T., Bielawska, A., Obeid, L.M. and Hannun, Y.A., 1994, Role of ceramide-activated protein phosphatase in ceramide-mediated signal transduction. J. Biot. Chem. 269 19605-19609. 

Ceramide has been shown to regulate directly or indirectly kinase suppressor of Ras (KSR identical to ceramide-activated protein kinase) (Basu et al, 1998), a ceramide-activated protein phosphatase (Dobrowsky... 

Ceramide-activated protein phosphatase Protein kinase C isoforms alpha, delta and zeta c-Raf-1 ... 

Dobrowsky, R.T. and Hanmm, Y.A., 1993, Ceramide-activated protein phosphatase partial purification and relationship to protein phosphatase 2A.Arfv. Lipid Res. 25 91-104... 

Kowluru A, Metz SA. Ceramide-activated protein phosphatase-2A activity in insulin-secreting cells. FEES Lett. 1997 418 179-182. 

Chalfant CE, Kishikawa K, Mumby MC et al (1999) Long chain ceramides activate protein phosphatase-1 and protein phosphatase-2A. Activation is stereospecific and regulated by phosphatidic acid. J Biol Chem 274 20313-20317... 

Abbreviations used tumor necrosis factor-a (TNF-a), interferon-y (INF-y), interleukin-ip (IL-1P), sphingosine kinase (SK), protein kinase C (PKC), sphingomyelinase (SMase), extra-cellular-regulated mitogen-activated protein kinase (ERK), stress-activated protein kinase (SAPK), ceramide activated protein kinase (CAPK), ceramide activated protein phosphatase (CAPP), mitogen activated kinase (MEK), phosphatidylinositol-3-kinase (PI3K), phospholipase C (PLC), phospholipase D (PLD), SIPR (SIP receptor). 

The downstream targets of ceramide that are involved in apoptosis remain to be identified. A few potential targets have, however, been described. In A431 cells, Davis and co-workers showed that sphingomyelin induced phosphorylation of the epidermal growth factor receptor at a specific site, Thr 669 (Davis et al., 1988 Faucher et al., 1988 Countaway et al., 1989). This led to the description of a membrane-bound, Ca -independent protein kinase that is stimulated by ceramide (Mathias et al., 1991). Conversely, Hannun and co-workers have demonstrated that ceramide activates a member of the the heterotrimeric protein phosphatase 2A family in rat T9 glioma cells and have coined the term ceramide-activated protein phosphatase (CAPP) for this activity (Dobrowsky and Hannun,... 

It has previously been demonstrated that the addition of ceramide to cells in culture induced a marked decrease in the phosphorylation of total phosphoproteins. This ceramide-activated protein phosphatase (CAPP)... 

Chalfant, CE, Kishikawa, K, Bielawska, A and Hannun, YA (2000) Analysis of ceramide-activated protein phosphatases. Methods Enzymol, 312, 420-428. 

Galadari S, Kishikawa K, Kamibayashi C, Mumby MC, Hannun YA. Purification and characterization of ceramide-activated protein phosphatases. Biochemistry. 1998 37(32) 11232-11238. 

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