Profilin is involved in G1 to S phase progression and mitotic spindle orientation during Leishmania donovani cell division cycle.

Profilin is a multi-ligand binding protein, which is a key regulator of actin dynamics and involved in regulating several cellular functions. It is present in all eukaryotes, including trypanosomatids such as Leishmania. However, not much is known about its functions in these organisms.

Emerging Functions of Actins and Actin Binding Proteins in Trypanosomatids.

Actin is the major protein constituent of the cytoskeleton that performs wide range of cellular functions. It exists in monomeric and filamentous forms, dynamics of which is regulated by a large repertoire of actin binding proteins. However, not much was known about existence of these proteins in trypanosomatids, till the genome sequence data of three important organisms of this class, viz.

Actin sequestering protein, profilin, regulates intracellular vesicle transport in Leishmania.

Profilins are the key regulators of actin dynamics in all eukaryotic cells. However, little information is available on their biochemical properties and functions in kinetoplastids, such as Trypanosoma and Leishmania. We show here that Leishmania parasites express only one homolog of profilin (LdPfn), which catalyzes nucleotide exchange on G-actin and promotes actin polymerization at its low concentrations.

Deciphering the role of UBA-like domains in intraflagellar distribution and functions of myosin XXI in Leishmania.

Myosin XXI (Myo21) is a novel class of myosin present in all kinetoplastid parasites, such as Trypanosoma and Leishmania. This protein in Leishmania promastigotes is predominantly localized to the proximal region of the flagellum, and is involved in the flagellum assembly, cell motility and intracellular vesicle transport. As Myo21 contains two ubiquitin associated (UBA)-like domains (UBLD) in its amino acid sequence, we considered it of interest to analyze the role of these domains in the intracellular distribution and functions of this protein in Leishmania cells.

Rational association of genes with traits using a genome-scale gene network for Arabidopsis thaliana.

We introduce a rational approach for associating genes with plant traits by combined use of a genome-scale functional network and targeted reverse genetic screening. We present a probabilistic network (AraNet) of functional associations among 19,647 (73%) genes of the reference flowering plant Arabidopsis thaliana. AraNet associations are predictive for diverse biological pathways, and outperform predictions derived only from literature-based protein interactions, achieving 21% precision for 55% of genes.