Plasmodium falciparum Dynein Light Chain 1 Interacts with Actin/Myosin during Blood Stage Development

Abstract

Dynein light chain 1 (LC1), a member of the leucine-rich repeat protein family, has been shown to be engaged in controlling flagellar motility in Chlamydomonas reinhardtii and Trypanosoma brucei via its interaction with the dynein ␥ heavy chain. In Plasmodium falciparum, we have identified the LC1 ortholog, designated Pfdlc1. Negative attempts to disrupt the dlc1 gene by reverse genetic approaches in both P. falciparum and P. berghei suggest either its essentiality for parasite survival or the inaccessibility of its locus. Expression studies revealed high levels of DLC1 protein in late trophozoites and schizonts, pointing to an unexpected role of this protein in blood-stage parasites as they do not have flagella. Interactions studies and co-immunoprecipitation experiments revealed that PfDLC1 was able to bind to P. falciparum myosin A and actin 1. The PfDLC1 interacting domains present in P. falciparum myosin A and actin 1 were mapped to sequences containing SDIE and/or EEMKT motifs present in the upper 50-kDa segment of the myosin A head domain and in the subdomain IV of actin 1, respectively. Detection of PfDLC1 by fluorescence tagging and immunofluorescence staining using specific antibodies showed a cytoplasmic location similar to actin and immunofluorescence studies showed a co-localization of PfDLC1 and myosin A. Taken together, these findings suggest that PfDLC1 might play an important role in P. falciparum erythrocytic stages by its interaction with myosin A and actin 1, known to be essential for parasite development.Molecular motors that involve myosin, kinesin, and dynein complexes are considered to be the most important driving force responsible for the motility/mobility and the active transport of proteins and vesicles in eukaryotic cells. These motor proteins are powered by the hydrolysis of ATP and convert chemical energy into mechanical work. In Plasmodium falciparum, which is an obligate intracellular parasite, the active penetration across non-permissive biological barriers and host cells is powered by an actin/myosin-based motor complex located at the pellicle of parasites

Critical role for a stage-specific actin in male exflagellation of the malaria parasite

“…It remains a possibility that the paralysed axonemes in the actII(‐) parasites are a direct result of actin II missing from the organelle. We note that an interaction of the dynein light chain 1 (DLC1) with actin I in asexual blood stages of P. falciparum was described recently (Daher et al ., 2010), and this may be an interesting issue to explore further for actin II.…”

Plasmodium falciparumencodes a conserved active inhibitor-2 for Protein Phosphatase type 1: perspectives for novel anti-plasmodial therapy

“…All peptides were solubilized in PBS and used in an ELISA based assay as previously described [80]. Plates were coated with 50 μg/ml (100 μl) of each peptide proteins or 10 μg/ml of PfI2WT in PBS overnight at 4°C.…”

Inhibition of Protein-protein Interactions in Plasmodium falciparum: Future Drug Targets

“…Concerning PfLRR7, its deduced amino acids sequence revealed significant identity with the dynein light chain of Chlamydomonas reinhardtii [63]. The dynein motor complex has been previously described to play a role in the regulation of flagella motility in algae and trypanosomes [73].…”

“…Among the 14 PfLRRs that we identified, PfLRR1 and PfLRR7 were selected for further characterization, based on their potential interaction with Protein Phosphatase 1 (PP1) [62] and actin respectively [63].…”