Interaction of influenza virus haemagglutinin with sphingolipid-cholesterol membrane domains via its transmembrane domain

Abstract

Sphingolipid–cholesterol rafts are microdomains in biological membranes with liquid‐ordered phase properties which are implicated in membrane traffic and signalling events. We have used influenza virus haemagglutinin (HA) as a model protein to analyse the interaction of transmembrane proteins with these microdomains. Here we demonstrate that raft association is an intrinsic property encoded in the protein. Mutant HA molecules with foreign transmembrane domain (TMD) sequences lose their ability to associate with the lipid microdomains, and mutations in the HA TMD reveal a requirement for hydrophobic residues in contact with the exoplasmic leaflet of the membrane. We also provide experimental evidence that cholesterol is critically required for association of proteins with lipid rafts. Our data suggest that the binding to specific membrane domains can be encoded in transmembrane proteins and that this information will be used for polarized sorting and signal transduction processes.

Recruitment of activating NK‐cell receptors 2B4 and NKG2D to membrane microdomains in mammalian cells is dependent on their transmembrane regions

“…It is also of note that this segment is mostly formed by hydrophobic amino acids. A similar requirement for hydrophobic amino acids in the luminal side of the transmembrane domain for a membrane microdomain association has been observed for the viral transmembrane protein hemagglutinin [47] and specific motifs for the association with sphingolipids have been detected in other proteins [48]. Therefore, this part of the 2B4 transmembrane domain might be lubricated with sphingolipids or other lipid species, thereby contributing to the DRM recruitment of the receptor.…”

Cholesterol depletion alters detergent-specific solubility profiles of selected tight junction proteins and the phosphorylation of occludin

“…A number of biochemical and structural features of integral membrane proteins promote their inclusion in DRMs. These include: a. interactions between lipids and hydrophobic amino acid sequences in the trans-membrane domain [23], b. single and double acylation of specific amino acid side chains [21], c. addition of glycosylphosphatidylinositol anchors [24] and d. a close physical association with CH [7,25]. Many of the proteins associated with DRMs are involved in signaling pathways [21].…”

Cholesterol-sensitive Modulation of Transcytosis

“…It is possible that the association of pIgR (bound to dIgA) or hTfnR with DRMs is accomplished by transmembrane domains interacting with certain classes of lipids enriched in lipid rafts (Scheiffele et al, 1997;Shvartsman et al, 2003). The size of these domains could be increased in response to protein oligomerization (Harder et al, 1998).…”