GRA Proteins of Toxoplasma gondii: Maintenance of Host-Parasite Interactions across the Parasitophorous Vacuolar Membrane

The dense granule of Toxoplasma gondii is a secretory vesicular organelle of which the proteins participate in the modification of the parasitophorous vacuole (PV) and PV membrane for the maintenance of intracellular parasitism in almost all nucleated host cells. In this review, the archives on the research of GRA proteins are reviewed on the foci of finding GRA proteins, characterizing molecular aspects, usefulness in diagnostic antigen, and vaccine trials in addition to some functions in host-parasite interactions.

The maturation of convoluted granular tubule cells from mouse submandibular glands during its postnatal development: increase in the cell size

We studied the evolution of nuclear and cytoplasmic volume and of the cytoplasm-nucleus ratio of convoluted granular tubule secretory cells in the submandibular glands of male albino Swiss mice at 21, 28, 35, 42 and 56 days of age. Nuclear volume was measured on 0.25um sections by morphometric method of Bach and the volume densities of nucleus and cytoplasm were determined by point-count volmetry. The date were used to calculate the cytoplasm/nucleus ratio and cytoplasmic volume. The nuclear volume of convoluted tubule cells decreased by 44.6% over the study period, where as the cytoplasmic volume increased markedly by 126.2% from 21 to 35 days of postnatal life, with no statiscally significant increases occurring thereafter. The cytoplasm/nucleus ratio increased by 331.3% over the study period

Patterns of transient expression of the arenavirus nucleocapsid protein gene in transfected cells

Los genes clonados de las proteínas de nucleocápside, N, de los arenavirus Junín y LCM (choriomeningitis linfocitaria) se insertaron en el vector de expresión pKG4 regulado por el promotor tardío del virus SV40. Cuando estas construcciones se utilizaron para transfectar las líneas celulares BHK-21 (fibroblastos de hamster lactante) y CV-1 (fibroblastos de riñón de mono verde africano) se observó la expresión transiente de un polipéptido de tamaño e inmunoreactividad indistinguible de la proteína N sintetizada durante una infección viral. El análisis por inmunofluorescencia reveló un patrón de distribución intracelular semejante al observado en células infectadas. Este patrón presentó variaciones desde una tinción citoplásmica difusa hasta gránulos citoplásmicos dispersos o concentrados en la zona perinuclear. La asociación de la proteína N con gránulos basófilos es semejante a la descripta en el efecto citópático causado por los arenavirus en las células infectadas, y podría relacionarse con las características fisicoquímicas de la proteina N, que contiene numerosas secuencias de aminoácidos básicos capaces de interactuar con ácidos ribonucleicos celulares