To examine whether human ATP-binding cassette (ABC) transporters play a role in the detoxification of plant alkaloid berberine, we investigated berberine transport using multidrug resistance protein1 (MDR1) and multidrug resistance-associated protein1 (MRP1). Cells expressing MDR1 or MRP1 accumulated less berberine. Berberine accumulation depended on the cellular ATP level, and was reversed by ...

Host cell invasion by Apicomplexan parasites marks a crucial step in disease establishment and pathogenesis. The moving junction (MJ) is a conserved and essential feature among parasites of this phylum during host cell invasion, thus proteins that associate at this MJ are potential targets of drug and vaccine development. In both Toxoplasma gondii and Plasmodium falciparum, a micronemal protein...

Monoclonal antibody (mAb) Tg786 against Toxoplasma gondii has been found to detect a 42-kDa rhoptry protein (ROP6) which showed protease activity and host cell binding characteristics after secretion. Using the mAb, a colony containing a 3o-UTR was probed in a T. gondii cDNA expression library. A full length cDNA sequence of the rhoptry protein was completed after 5o-RACE, which consisted of 1,...

Apicomplexans are obligate intracellular parasites that actively penetrate their host cells to create an intracellular niche for replication. Commitment to invasion is thought to be mediated by the rhoptries, specialized apical secretory organelles that inject a protein complex into the host cell to form a tight-junction for parasite entry. Little is known about the molecular factors that gover...

Mating of compatible haploid cells of Ustilago maydis is essential for infection and disease development in the host. For mating and subsequent filamentous growth and pathogenicity, the transcription factor, prf1 is necessary. Prf1 is in turn regulated by the cAMP and MAPK pathways and other regulators like rop1 and hap1. Here we describe the identification of another putative Prf1 regulator, m...

Some apicomplexan parasites have evolved distinct protein kinase families to modulate host cell structure and function. Toxoplasma gondii rhoptry protein kinases and pseudokinases are involved in virulence and modulation of host cell signalling. The proteome of Plasmodium falciparum contains a family of putative kinases called FIKKs, some of which are exported to the host red blood cell and mig...

It is important to classify retinopathy of prematurity (ROP) in each eye, at each screening session. Doing so makes it possible to screen babies consistently and to make decisions about whether further screening is required and when, or whether laser treatment or surgical management is needed. The International Committee for the Classification of ROP1 has classified it using the following crite...

The invasion of erythrocytes by Plasmodium merozoites requires specific interactions between host receptors and parasite ligands. Parasite proteins that bind erythrocyte receptors during invasion are localized in apical organelles called micronemes and rhoptries. The regulated secretion of microneme and rhoptry proteins to the merozoite surface to enable receptor binding is a critical step in t...