Sub-grouping and sub-functionalization of the RIFIN multi-copy protein family

Abstract

Background: Parasitic protozoans possess many multicopy gene families which have central roles in parasite survival and virulence. The number and variability of members of these gene families often make it difficult to predict possible functions of the encoded proteins. The families of extracellular proteins that are exposed to a host immune response have been driven via immune selection to become antigenically variant, and thereby avoid immune recognition while maintaining protein function to establish a chronic infection.

Proteins of the Plasmodium falciparum two transmembrane Maurer’s cleft protein family, PfMC-2TM, and the 130 kDa Maurer’s cleft protein define different domains of the infected erythrocyte intramembranous network

“…In addition, due to the orientation and conformation of PfMC-2TM, different epitopes on the protein may be differentially accessible and may explain the different patterns of reactivity obtained with the different peptide antibodies against PfMC-2TM. Differential localization of three transmembrane proteins RIFIN, MAHRP1, and STEVOR have been reported using different antibodies, including anti-GFP antibodies (for transfectants; Joannin et al 2008;Khattab and Klinkert 2006;Petter et al 2007;Spycher et al 2006). The differential antibody recognition pattern obtained with the peptide-specific antibodies does not appear to be due to protein processing or precursor product relationships since we do not observe differential protein banding by western blotting.…”

Plasmodium falciparum complicated malaria: Modulation and connectivity between exportome and variant surface antigen gene families

“…A and B type) based on the presence or absence of a 25 amino acid sequence motif (Joannin et al, 2008, Tham et al, 2007. RIFINs have been reported to be expressed in various asexual (intraerythrocytic, merozoite and sporozoite stages) and sexual stages of the parasite's life cycle (Bozdech et al, 2003, Florens et al, 2002, Le Roch et al, 2003.…”

“…The Array also contains specific probes for 23 stevor genes out of 26 genes reported to be present in the HB3 strain (Joannin et al, 2008). Transcripts were detected from 12 stevor genes of the HB3 strain ( Supplementary Fig.…”

Comprehensive annotation of Glossina pallidipes salivary gland hypertrophy virus from Ethiopian tsetse flies: a proteogenomics approach

“…For instance, ORF SGHV-Eth016 contained an NAD-specific glutamate dehydrogenase (GluDH) motif, whilst ORF SGHV-Eth028 contained the subtelomic variant ORF and repetitive interspersed family (Rif/Stevor) domain. Stevor and Rif family proteins are implicated in the regulation of antigenic variations and gene duplication events in some pathogens (Joannin et al, 2008;Niang et al, 2009), but their role in viruses is not well studied. ORF SGHVEth110 contained a viral small hydrophobic protein (v-SHP) domain, which is a retention signal for intracellular microvesicles (McCarthy & Theilmann, 2008) potentially involved in virus docking.…”