A Novel Family of Toxoplasma IMC Proteins Displays a Hierarchical Organization and Functions in Coordinating Parasite Division

Apicomplexans employ a peripheral membrane system called the inner membrane complex (IMC) for critical processes such as host cell invasion and daughter cell formation. We have identified a family of proteins that define novel sub-compartments of the Toxoplasma gondii IMC. These IMC Sub-compartment Proteins, ISP1, 2 and 3, are conserved throughout the Apicomplexa, but do not appear to be present outside the phylum. ISP1 localizes to the apical cap portion of the IMC, while ISP2 localizes to a central IMC region and ISP3 localizes to a central plus basal region of the complex. Targeting of all three ISPs is dependent upon N-terminal residues predicted for coordinated myristoylation and palmitoylation. Surprisingly, we show that disruption of ISP1 results in a dramatic relocalization of ISP2 and ISP3 to the apical cap. Although the N-terminal region of ISP1 is necessary and sufficient for apical cap targeting, exclusion of other family members requires the remaining C-terminal region of the protein. This gate-keeping function of ISP1 reveals an unprecedented mechanism of interactive and hierarchical targeting of proteins to establish these unique sub-compartments in the Toxoplasma IMC. Finally, we show that loss of ISP2 results in severe defects in daughter cell formation during endodyogeny, indicating a role for the ISP proteins in coordinating this unique process of Toxoplasma replication

A Novel PAN/Apple Domain-Containing Protein from Toxoplasma gondii: Characterization and Receptor Identification

Toxoplasma gondii is an intracellular parasite that invades nucleated cells, causing toxoplasmosis in humans and animals worldwide. The extremely wide range of hosts susceptible to T. gondii is thought to be the result of interactions between T. gondii ligands and receptors on its target cells. In this study, a host cell-binding protein from T. gondii was characterized, and one of its receptors was identified. P104 (GenBank Access. No. CAJ20677) is 991 amino acids in length, containing a putative 26 amino acid signal peptide and 10 PAN/apple domains, and shows low homology to other identified PAN/apple domain-containing molecules. A 104-kDa host cell-binding protein was detected in the T. gondii lysate. Immunofluorescence assays detected P104 at the apical end of extracellular T. gondii. An Fc-fusion protein of the P104 N-terminus, which contains two PAN/apple domains, showed strong affinity for the mammalian and insect cells evaluated. This binding was not related to protein-protein or protein-lipid interactions, but to a protein-glycosaminoglycan (GAG) interaction. Chondroitin sulfate (CS), a kind of GAG, was shown to be involved in adhesion of the Fc-P104 N-terminus fusion protein to host cells. These results suggest that P104, expressed at the apical end of the extracellular parasite, may function as a ligand in the attachment of T. gondii to CS or other receptors on the host cell, facilitating invasion by the parasite

My career chapter as a tool for reflective practice

This paper addresses reflective practice in research and practice and takes the issue of consciousness of social class in vocational psychology as a working example. It is argued that the discipline’s appreciation of social class can be advanced through application of the qualitative research method autoethnography. Excerpts from an autoethnographic study are used to explore the method’s potential. This reflexive research method is presented as a potential vehicle to improve vocational psychologists’ own class consciousness, and to concomitantly enhance their capacity to grasp social class within their own spheres of research and practice. It is recommended that autoethnography be used for research, training, and professional development for vocational psychologists

Relationships between Use of Long Acting Antipsychotics and Sociodemographic and Clinical Characteristics of Patients with Schizophrenia

Objective: Schizophrenia is a chronic psychiatric disorder that causes severe sociooccupational disability. The primary goal of treatment is to prevent a subsequent relapse and restore sociooccupational functioning to the premorbid level. However, high rates of relapses can be seen during the illness due to inadequate adherence to drug therapy. Long acting injectable (LAI) antipsychotics aim to promote compliance in individuals with particularly severe mental illnesses, thereby enhancing relapse prevention. In the literature, there are limited numbers of studies, which have investigated the relationships between use of LAI antipsychotics and sociodemographical and clinical characteristics of schizophrenic patients. In this study, we aimed to identify the association between sociodemographic and clinical characteristics of patients with schizophrenia and use of long acting antipsychotics. Methods: This was a retrospective cohort study. The data of 252 patients with a diagnosis of schizophrenia were obtained from the medical records of the psychiatry departments of Kirklareli State Hospital and Golbasi State Hospital. The patients were grouped according to whether they had used LAI antipsychotics or not. The sociodemographic and clinical characteristics were compared between patients with and without use of long acting antipsychotics. Results: In the LAI antipsychotic group (n=96), onset of illness was earlier and duration of schizophrenia was longer. The percentage of history of violent behaviour, suicide attempts and family history of schizophrenia were significantly higher in the LAI antipsychotic group. An earlier age of onset, a more significant history of suicide attempts, a history of violent behaviour and a family history of schizophrenia were found to be predictors of LAI antipsychotic use. Conclusion: Relapses due to poor adherence to treatment can be overcome by LAI antipsychotics. In addition to the familiar causes of nonadherence, the specific predictors of use of LAI antipsychotics should be carefully noted and patients should be initiated on LAI antipsychotics even when they are in the early phases of illness