Abstract |
Prosaposin is a neurotrophic factor that has been demonstrated to mediate trophic signalling events in different cell types; it distributes to surface membranes of neural cells and also exists as a secreted protein in different body fluids. Prosaposin was demonstrated to form tightly bound complexes with a variety of gangliosides, and a functional role has been suggested for ganglioside-prosaposin complexes. In this work, we provide evidence that exogenous prosaposin triggers a signal cascade after binding to its target molecules on lipid rafts of pheochromocytoma PC12 cell plasma membranes, as revealed by scanning confocal microscopy and linear sucrose gradient analysis. In these cells, prosaposin is able to induce extracellular signal-regulated kinase phosphorylation, sphingosine kinase activation, and consequent cell death prevention, acting through lipid rafts. These findings point to the role of lipid rafts in the prosaposin-triggered signalling pathway, thus supporting a role for this factor as a new component of the multimolecular signalling complex involved in the neurotrophic response.
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Authors | Maurizio Sorice, Sabrina Molinari, Luisa Di Marzio, Vincenzo Mattei, Vincenzo Tasciotti, Laura Ciarlo, Masao Hiraiwa, Tina Garofalo, Roberta Misasi |
Journal | The FEBS journal
(FEBS J)
Vol. 275
Issue 19
Pg. 4903-12
(Oct 2008)
ISSN: 1742-464X [Print] England |
PMID | 18761669
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Low Density Lipoprotein Receptor-Related Protein-1
- PSAP protein, human
- Saposins
- Phosphotransferases (Alcohol Group Acceptor)
- sphingosine kinase
- Extracellular Signal-Regulated MAP Kinases
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Topics |
- Animals
- Apoptosis
(drug effects)
- Enzyme Activation
- Extracellular Signal-Regulated MAP Kinases
(metabolism)
- Humans
- Low Density Lipoprotein Receptor-Related Protein-1
(metabolism)
- Membrane Microdomains
(physiology)
- PC12 Cells
- Phosphotransferases (Alcohol Group Acceptor)
(metabolism)
- Rats
- Saposins
(physiology)
- Signal Transduction
(physiology)
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