A single-cell secretion assay was used to detect cells that secrete products which react with an antiserum that binds T cell antigen-binding polypeptides. The antiserum (R11), which was produced by immunization of rabbits with a murine trinitrophenyl-specific suppressor factor, reacts with T cells and their products and with a suppressor T-cell clone but not with B cells or their products. The ...

Regulated secretory cells have two pathways that transport secreted proteins from the Golgi complex to the cell surface. To identify carrier vesicles involved in regulated and constitutive secretion, PC12 pheochromocytoma cells were labeled with [35S]sulfate to identify markers for the two secretory pathways, then mechanically permeabilized and incubated in vitro. Small constitutive secretory v...

Sec14p homology domains are found in a large number of proteins from plants, yeast, invertebrates, and higher eukaryotes. We report that the N-terminal Sec14p homology domain of the human protein tyrosine phosphatase PTP-MEG2 binds phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P(3)) in vitro and colocalizes with this lipid on secretory vesicle membranes in intact cells. Point mutations...

The giant anteater (Myrmecophaga tridactyla) is a vulnerable species from Central and South America, considered possibly extinct in Belize, Guatemala, El Salvador, Uruguay. Due to the species’ conservation reproductive importance, this research aimed characterize morphology, histochemical, immunohistochemical, ultrastructural feature of prostate gland. For this, we collected 11 glands performed...

Natural killer (NK) cells play important roles in defense against tumor, viral infection, and cell-mediated xenograft rejection through secretion of secretory lysosomes. In this study, we used high time-resolution membrane capacitance measurement and fluorescence-imaging techniques to study the biogenesis and exocytosis of secretory lysosomes in a human NK cell line. We demonstrated a high-affi...

Tear proteins are supplied by the regulated fusion of secretory vesicles at the apical surface of lacrimal gland acinar cells, utilizing trafficking mechanisms largely yet uncharacterized. We investigated the role of Rab27b in the terminal release of these secretory vesicles. Confocal fluorescence microscopy analysis of primary cultured rabbit lacrimal gland acinar cells revealed that Rab27b wa...

1. The incorporation of tritiated glucose into bronchial gland cells enables their glycoprotein secretion to be followed by radioautography. The number of cells from which secretion is observed after 4 h of cell culture is the secretory index. 2. Large variations in secretory index were observed between the bronchi of different subjects, but the secretory index was proportional to gland size. 3...

Seasonal variations in the secretory activity of the subcommissural organ (SCO) of snakes and turtles was studied by immunocytochemistry, lectins, and electron microscopy. In animals sacrificed in summer, immunoreactive material, mostly devoid of sialic acid, occupied the whole cytoplasm. Cells showed many distended cisternae of rough endoplasmic reticulum and secretory granules. In animals sac...

Organelles are not uniformly distributed throughout the cytoplasm but have preferred locations that vary between tissues and during development. To investigate organelle targeting to cytoplasmic domains we have taken advantage of the mouse pituitary cell line, AtT-20, which, when induced to extend long processes, accumulates dense core secretory granules at the tips of the processes. During mit...

The present study describes the cyclical changes in the secretory activity of the Cowper’s gland in the Indian fruit bat, Rousettus leschenaulti. The secretory activity in the Cowper’s gland during the breedingquiescence cycle is not well marked in Rousettus. During the sexually quiescent period (July), Cowper’s glands are regressed, acini are small and are lined by low columnar cells with dark...