C. of SBP1 that binds specifically to defined subdomains of two major components of the RBC membrane skeleton, protein 4.1R and spectrin. We show that these interactions serve as one mechanism to anchor MCs to the RBC membrane skeleton, however, while they appear to be necessary, they are not sufficient for the translocation of PfEMP1 onto the RBC surface. The N-terminal domain name of SBP1 that resides within the lumen of MCs clearly plays an essential, but presently unknown role in this process. that infect humans and its YAP1 propensity to cause severe, often fatal disease, is usually underpinned by its ability to make the reddish blood cell (RBC) in which it resides abnormally adhesive for a number of other cell types including vascular endothelial cells, placental syncytiotrophoblasts, platelets, and other infected or non-infected RBCs. Consequently, RBCs infected with mature stages of cease to circulate and build up in multiple organs including the brain and placenta with subsequent severe pathological effects (observe [3C5] for reviews). The altered adhesive properties of parasitised RBCs Succinyl phosphonate trisodium salt (PRBCs) is usually mediated by a family of high molecular excess weight, antigenically-diverse, parasite-encoded proteins collectively called erythrocyte protein 1 (PfEMP1) that are transcribed from your multi-gene family and offered on the surface of RBCs infected with mature-stage parasites. Different variants of PfEMP1 can bind to a number of host receptors, principally CD36 and intracellular adhesion molecule-1 (ICAM-1), expressed on the surface of vascular endothelial cells, and chondroitin sulphate A (CSA) in the placenta [3]. The ability of PfEMP1 to mediate adhesion is dependent on its correct presentation around the PRBC surface [6C9]. We as well as others have previously shown that a parasite-encoded protein, skeleton-binding protein 1 (SBP1), is essential for trafficking and translocation of PfEMP1 onto the RBC surface and consequently for adhesion of PRBCs to the vascular endothelium [10,11]. SBP1 is usually a trans-membrane protein, located in parasite-induced membranous structures within the PRBC cytoplasm Succinyl phosphonate trisodium salt known as Maurer’s clefts (MCs) [12,13]. The topology of SBP1 is usually such that its entire N-terminal domain name (SBP1-N; Fig. 1) is usually enclosed within in the lumen of the MC while its relatively shorter C-terminal tail (SBP1-C; Fig. 1) is usually exposed on the outside of the cleft, facing into the RBC cytosol [14]. Interestingly, disruption of the gene encoding SBP1 in appears to alter the cellular distribution of MCs, such that in RBCs infected with transgenic parasites lacking SBP1 expression, MCs are located further from your RBC membrane skeleton than in RBCs infected with wild-type parasites [10]. We therefore hypothesised that SBP1-C or domains within it bind specifically to protein components of the RBC membrane skeleton and mediate transfer of PfEMP1 from MCs onto the PRBC surface. To test this Succinyl phosphonate trisodium salt hypothesis, we have used a combination of molecular, cellular and biophysical approaches to identify the proteins (and sub-domains within them) that partake in this pathophysiologically-important conversation. Our studies provide a better understanding of the function of the C-terminal domain name of SBP1, its role in the association MCs with the RBC membrane skeleton and the placement of PfEMP1 onto the surface of PRBCs. Open in a separate windows Fig. 1 Association of the C-terminal domain name of SBP1 with the RBC membrane skeleton. A. Schematic representation of SBP1. Repeat regions (light grey) and the trans-membrane domain name (TM) are indicated. B. Binding of the SBP1 C-terminal domain name (SBP1-C) to the RBC skeleton. RBCs resealed with recombinant SBP1-C appended to YFP (SBP1-CCYFP;.