Related Experiment Video

Updated: Aug 8, 2025

Protocol for Plasmodium falciparum Infections in Mosquitoes and Infection Phenotype Determination
14:10

Protocol for Plasmodium falciparum Infections in Mosquitoes and Infection Phenotype Determination

Published on: July 4, 2007

18.0K

Structure and function of Plasmodium actin II in the parasite mosquito stages

Andrea J Lopez1, Maria Andreadaki2, Juha Vahokoski1

  • 1Department of Biomedicine, University of Bergen, Bergen, Norway.

Plos Pathogens
|March 6, 2023
PubMed

Insights

Plasmodium actin II, crucial for malaria parasite reproduction, forms stable filaments essential for male gametogenesis and oocyst development. Its structure and function are key to understanding parasite biology.

Area of Science:

  • Molecular Biology
  • Parasitology
  • Structural Biology

Background:

  • Actins are essential eukaryotic proteins involved in cellular processes.
  • Malaria parasites (Plasmodium spp.) possess two unique actin isoforms, actin I and actin II.
  • Actin II's structure and function, particularly in gametogenesis and oocyst development, remain less understood compared to actin I.

Purpose of the Study:

  • To elucidate the structure, filament formation, and biochemical properties of Plasmodium actin II.
  • To investigate the essential functions of actin II in male gametogenesis and the oocyst stage.
  • To understand the structural basis for actin II's filament stability and functional regulation.

Main Methods:

  • Expression analysis in Plasmodium gametocytes and zygotes.
  • High-resolution structural determination of actin II filaments.
  • Biochemical characterization, including in vitro filament formation and polymerization kinetics.
  • Mutational analysis to probe functional requirements, including histidine 73 methylation.

Main Results:

  • Actin II is expressed in male gametocytes and zygotes, localizing to filament-like structures near the nucleus.
  • Actin II readily forms long, stable filaments in vitro, with near-atomic structures revealing subtle differences from canonical actins.
  • Mutational studies indicate stable actin II filaments are vital for male gametogenesis, while oocyst function depends on methylation of histidine 73.
  • Actin II polymerization follows a classical nucleation-elongation mechanism with a critical concentration of ~0.1 μM.

Conclusions:

  • Plasmodium actin II possesses unique structural features contributing to filament stability, essential for its roles in parasite development.
  • Actin II's functions in male gametogenesis and oocyst development are critical for parasite survival and transmission.
  • Fine-tuned regulation, including methylation, is crucial for actin II's diverse functions within the malaria parasite lifecycle.

More Related Videos

Phenotypic Analysis of Rodent Malaria Parasite Asexual and Sexual Blood Stages and Mosquito Stages08:23

Phenotypic Analysis of Rodent Malaria Parasite Asexual and Sexual Blood Stages and Mosquito Stages

Published on: May 30, 2019

11.6K
Standard Membrane Feeding Assay for the Detection of Plasmodium falciparum Infection in Anopheles Mosquito Vectors05:28

Standard Membrane Feeding Assay for the Detection of Plasmodium falciparum Infection in Anopheles Mosquito Vectors

Published on: May 12, 2022

3.1K

Related Concept Videos

Symbiosis00:58

Symbiosis

Symbiotic relationships are long-term, close interactions between individuals of different species that affect the distribution and abundance of those species. When a relationship is beneficial to both species, this is called mutualism. When the relationship is beneficial to one species but neither beneficial nor harmful to the other species, this is called commensalism. When one organism is harmed to benefit another, the relationship is known as parasitism. These types of relationships often...
29.4K
Diversity of Protists II01:27

Diversity of Protists II

Alveolates are a group of organisms recognized by the presence of alveoli, which are cytoplasmic sacs located beneath the cell membrane. While their function remains uncertain, alveoli may help regulate water balance by controlling how much water enters and leaves the cell. In dinoflagellates, these structures may serve as armor plates. There are three major types of alveolates: ciliates, which move using cilia; dinoflagellates, which use flagella for movement; and apicomplexans, which are...
79
Mechanism of Filopodia Formation01:39

Mechanism of Filopodia Formation

Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
2.4K
Overview of Myosin Structure and Function01:15

Overview of Myosin Structure and Function

Myosins are a family of molecular motor proteins, first identified in the skeletal muscles, where they are responsible for muscle contraction. Along with their role in muscle contraction, these proteins also play a role in the intracellular transport of molecules and vesicles. There are twenty-four classes of myosins based on their domain sequence and organization. Of the twenty-four, six classes (Myosin I, Myosin II, Myosin V, Myosin VI, Myosin VII, and Myosin X)  have been well...
4.5K
Microtubules in Cell Motility01:24

Microtubules in Cell Motility

Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
3.3K
The Role of Actin and Myosin in Non-muscle Cells01:10

The Role of Actin and Myosin in Non-muscle Cells

Actin and myosin or actomyosin filaments also play a significant role in cells other than those involved in muscle contraction (which occurs within the sarcomere of muscle cells). The mechanism of non-muscle cell contractile bundles was first observed in Dictyostelium and Acanthamoeba. In non-muscle cells, two bundles are commonly found: stress fibers and actomyosin adherence belts. These contractile bundles are smaller and less organized than the ones found in muscle cells. They  are held...
3.6K