Signaling through sphingolipid microdomains of the plasma membrane: The concept of signaling platform

Hoessli, D.C and Ilangumaran, S. and Soltermann, A. and Robinson, P.J and Borisch, B. and Din, N.U (2000) Signaling through sphingolipid microdomains of the plasma membrane: The concept of signaling platform. Glycoconjugate Journal, 17 (3-4). pp. 191-197. ISSN 0282-0080. (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1023/A:1026585006064

Abstract

Transmembrane signaling requires modular interactions between signaling proteins, phosphorylation or dephosphorylation of the interacting protein partners [1] and temporary elaboration of supramolecular structures [2], to convey the molecular information from the cell surface to the nucleus. Such signaling complexes at the plasma membrane are instrumental In translating the extracellular cues into intracellular signals for gene activation. In the most straightforward case, ligand binding promotes homodimerization of the transmembrane receptor which facilitates modular interactions between the receptor's cytoplasmic domains and intracellular signaling and adaptor proteins [3]. For example, most growth factor receptors contain a cytoplasmic protein tyrosine kinase (PTK) domain and ligand-mediated receptor dimerization leads to cross phosphorylation of tyrosines in the receptor's cytoplasmic domains, an event that initiates the signaling cascade [4]. In other signaling pathways where the receptors have no intrinsic kinase activity, intracellular nonreceptor PTKs (i.e. Src family PTKs, JAKs) are recruited to the cytoplasmic domain of the engaged receptor. Execution of these initial phosphorylations and their translation into efficient cellular stimulation requires concomitant activation of diverse signaling pathways. Availability of stable, preassembled matrices at the plasma membrane would facilitate scaffolding of a large array of receptors, coreceptors, tyrosine kinases and other signaling and adapter proteins, as it is the case in signaling via the T cell antigen receptor [5]. The concept of the signaling platform [6] has gained usage to characterize the membrane structure where many different membrane-bound components need to be assembled in a coordinated manner to carry out signaling. The structural basis of the signaling platform lies in preferential assembly of certain classes of lipids into distinct physical and functional compartments within the plasma membrane [7,8]. These membrane microdomains or rafts (Figure 1) serve as privileged sites where receptors and proximal signaling molecules optimally interact [9]. In this review, we shall discuss first how signaling platforms are assembled and how receptors and their signaling machinery could be functionally linked in such structures. The second part of our review will deal with selected examples of raft-based signaling pathways in T lymphocytes and NK cells to illustrate the ways in which rafts may facilitate signaling.

Item Type: Article
Uncontrolled keywords: rafts; transmembrane signaling; sphingolipids; protein tyrosine kinase
Subjects: Q Science
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: O.O. Odanye
Date Deposited: 03 Apr 2009 10:12
Last Modified: 03 Apr 2009 10:12
Resource URI: http://kar.kent.ac.uk/id/eprint/16220 (The current URI for this page, for reference purposes)
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