Skip Navigation

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by Einicker-Lamas, M.
Right arrow Articles by Vieyra, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Einicker-Lamas, M.
Right arrow Articles by Vieyra, A.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

J. Biochem, 2003, Vol. 134, No. 4 529-536
© 2003 Japanese Biochemical Society

BIOCHEMISTRY

Sphingosine-1-Phosphate Formation Activates Phosphatidylinositol-4 Kinase in Basolateral Membranes from Kidney Cells: Crosstalk in Cell Signaling through Sphingolipids and Phospholipids

Marcelo Einicker-Lamas*,1, Leandro D. Wenceslau1, Robson R. Bernardo1, Luciana Nogaroli1, Adilson Guilherme2, Mecia M. Oliveira1 and Adalberto Vieyra§,1

1 Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil; and 2 University of Massachusetts Medical School, Worcester, MA 01605, USA

Sphingosine-1-phosphate (S1P) and phosphatidylinositol-4 phosphate [PtdIns(4)P] are important second messengers in various cellular processes. Here, we show that S1P and PtdIns(4)P are formed in purified basolateral membranes (BLM) derived from kidney proximal tubules, indicating the presence of a plasma membrane associated SPK (BLM-SPK) and phosphatidylinositol-4 kinase (PI-4K). We observed that S1P synthesis is linear with time, dependent on protein concentration, and saturable in the presence of increasing concentrations of sphingosine. Different from the observations on cytosolic SPKs, the formation of S1P by BLM-SPK is Mg2+-independent and insensitive to the classical inhibitor of the cytosolic SPKs, DL-threo-dihydrosphingosine. With sphingosine as substrate, the enzyme shows cooperative kinetics (n = 3.4) with a K0.5 value of 0.12 mM, suggesting that BLM-SPK is different from the previously characterized cytosolic SPK. The formation of PtdIns(4)P markedly inhibits BLM-SPK activity. Conversely, a strong activation of PtdIns(4)P synthesis by the formation of S1P is observed. Taken together, these results indicate that (i) basolateral membranes from kidney cells harbor a SPK activity that potentially regulates renal epithelium function, and (ii) the formation of S1P mediated by SPK enhances PI-4K activity, while PtdIns(4)P in turn inhibits SPK, suggesting an interplay between these lipid signaling molecules. These findings suggest the possibility of crosstalk between sphingolipids and glycerolipids, which might be involved in the regulation of transepithelial fluxes across the BLM of kidney cells.

* M.E-L. holds a PROFIX fellowship from CNPq-Brazil. L.D.W. is a recipient of a fellowship from CNPq/PIBIC (PINC Program, School of Medicine).

§ To whom correspondence should be adressed. Fax: +55-21-22808193, E-mail: avieyra{at}biof.ufrj.br


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
L. M. P. Cabral, M. Wengert, A. A. A. da Ressurreicao, P. H. P. Feres-Elias, F. G. Almeida, A. Vieyra, C. Caruso-Neves, and M. Einicker-Lamas
Ceramide Is a Potent Activator of Plasma Membrane Ca2+-ATPase from Kidney Proximal Tubule Cells with Protein Kinase A as an Intermediate
J. Biol. Chem., August 24, 2007; 282(34): 24599 - 24606.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.