Electron microscopy of directly frozen giant cells of characean algae shows a continuous, tridimensional network of anastomosing tubes and cisternae of rough endoplasmic reticulum which pervade the streaming region of their cytoplasm. Portions of this endoplasmic reticulum contact the parallel bundles of actin filaments at the interface with the stationary cortical cytoplasm. Mitochondria, glyc...

OBJECTIVE Endoplasmic reticulum stress increases macrophage apoptosis, contributing to the complications of atherosclerosis. Insulin-resistant macrophages are more susceptible to endoplasmic reticulum stress-associated apoptosis probably contributing to macrophage death and necrotic core formation in atherosclerotic plaques in type 2 diabetes. However, the molecular mechanisms of increased apop...

The rate of synthesis of the endoplasmic reticulum in barley aleurone cells after treatment with gibberellic acid was determined by measurement of [(14)C]-choline incorporation into acid-insoluble material in a semipurified fraction containing the endoplasmic reticulum. 94% of the (14)C incorporated into this fraction is extractable by lipid solvents and only 9% is removed by procedures for nuc...

The endoplasmic reticulum contains a quality control system that subjects misfolded or unassembled secretory proteins to rapid degradation via the cytosolic ubiquitin proteasome system. This requires retrograde protein transport from the endoplasmic reticulum back to the cytosol. The Sec61 pore, the central component of the protein import channel into the endoplasmic reticulum, was identified a...

To determine if cardiogenesis causes endoplasmic reticulum stress, we examined chaperone expression. Many cardiac pathologies cause activation of the fetal gene program, and we asked the reverse: could activation of the fetal gene program during development induce endoplasmic reticulum stress/chaperones? We found stress related chaperones were more abundant in embryonic compared to adult hearts...

The envelope membrane of rat liver nuclei contains a P-type Ca(2+)-transporting pump, revealed by the presence of a Ca(2+)-stimulated phosphoenzyme. The level of the nuclear phosphoenzyme in autoradiographed polyacrylamide gels was decreased by lanthanum, as typically observed in the endoplasmic reticulum Ca2+ pump. It was also decreased by thapsigargin and 2,5-di-(tert-butyl)-1,4-benzohydroqui...

The potential pro-survival role of phosphatidylinositol 3-kinase (PI3K)/Akt during endoplasmic reticulum stress has been well-characterized. However, the detailed mechanisms remain largely unknown. Here, we showed that PI3K/Akt inhibition promoted endoplasmic reticulum stress-induced apoptosis in a glucose-regulated protein 78 (GRP78)-dependent manner. During endoplasmic reticulum stress, high ...

Neurons are highly polarized, but the trafficking mechanisms that operate in these cells and the topological organization of their secretory organelles are still poorly understood. Particularly incipient is our knowledge of the role of the neuronal endoplasmic reticulum. Here we review the current understanding of the endoplasmic reticulum in neurons, its structure, composition, dendritic distr...