Nina Monica Simon - OPUS - Universität Würzburg

________________________________________________________________Introduction
Figure 1.11: Expression of PfCCp proteins in gametocytes. Expression patterns in mature
gametocytes as determined by IFA. PfCCp1 through PfCCp3 show a punctuate pattern in
mature gametocytes, whereas PfCCp4 is homogenously expressed. PfCCp5 and PfFNPA
proteins are predominantly localized at the poles of the gametocytes. PfCCp expression is
shown in green, while erythrocytes are highlighted in red. Immunoelectron microscopic
shows PfCCp1 localization in the PV in association with the PPM, labelled with anti-
PfCCp1 primary antibody and immunogold (Pradel et al., 2004; Scholz et al., 2008).
subunits for TBV (Scholz et al., 2008). PfCCp1, PfCCp2, and PfCCp3 co-localize within
the PV of mature gametocytes (Pradel et al., 2006). It has been shown that PfCCp1,
PfCCp2, PfCCp3, PfCCp4, or PfFNPA knockout gametocytes exhibit reduced abundance
or an absence of other PfCCp proteins. This was observed only at protein and not on
transcript level (Pradel et al., 2006; Simon et al., 2009).
Adhesion domains of PfCCp proteins
PfCCp proteins are composed of various widely conserved adhesion domains and
contain a signal peptide (Fig. 1.12). The ricin domain of PfCCp1 and PfCCp2 is a
carbohydrate-binding domain which is widely distributed in bacteria, fungi, animals,
and plants. It is part of several carbohydrate and glycoprotein interacting proteins. The
widespread discoidin domain can be found in eukaryotes and bacteria and is able to
bind sugars and lipid head groups (Templeton et al., 2004). The neurexin-collagen
(NEC) domain consists of a deep cleft for ligand binding and exists in collagens,
fibrinogen family proteins, and neurexins. The name for PfCCp proteins is derived from
the ‘LCCL’ or ‘Limulus coagulation factor’ domain. The LCCL domain was first
discovered in the horseshoe crab (Limulus) and is composed of six conserved cysteine
residues which are found in all PfCCp proteins, except of PfFNPA. It is thought to be an
autonomously folding domain that has been found in various multi-domain proteins
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