Currently browsing: “Sebastián Bernales”

The unfolded protein response during prostate cancer development

KEYWORDS: ATF6 • IRE1 • PERK • Prostate cancer • Sebastián Bernales • Tumorigenesis • Unfolded protein response (UPR)

Accumulation of misfolded proteins in the endoplasmic reticulum (ER) induces the unfolded protein response (UPR). The UPR promotes cell survival by adjusting ER protein folding capacity but if homeostasis cannot be reestablished, apoptosis is induced. The execution of life/death decisions is regulated by the three UPR branches (IRE1, PERK, ATF6) and their downstream effectors. Events […]

Unfolded protein stress in the endoplasmic reticulum and mitochondria: a role in neurodegeneration

KEYWORDS: Alzheimer’s disease • endoplasmic reticulum • Mitochondria • Parkinson’s disease • Sebastián Bernales • unfolded protein response

Protein-folding occurs in several intracellular locations including the endoplasmic reticulum and mitochondria. In normal conditions there is a balance between the levels of unfolded proteins and protein folding machinery. Disruption of homeostasis and an accumulation of unfolded proteins trigger stress responses, or unfolded protein responses (UPR), in these organelles. These pathways signal to increase the […]

Role of dopamine in the physiology of T-cells and dendritic cells

KEYWORDS: CD8+ cytotoxic • Dendritic cells • Sebastián Bernales • T-cell mediated immunity • T-cells CD4+ helper • T-cells Dopamine

Dendritic cells (DCs) are responsible for priming T-cells and for promoting their differentiation from naïve T-cells into appropriate effector cells. Because of their fundamental roles in controlling immunity, DCs and T-cells require tight regulatory mechanisms. Several studies have shown that dopamine, not only mediate interactions into the nervous system, but can also contribute to the […]

Selective autophagy of the endoplasmic reticulum

KEYWORDS: electron microscopy • endoplasmic reticulum proliferation • ER stress • ER-containing autophagosome • organelle degradation • Sebastián Bernales • unfolded protein response

ABSTRACT: Throughout their life, cells must maintain homeostasis while facing constantly fluctuating demands on their different organelles. A major mechanism for the homeostatic control of organelle function is the unfolded protein response (UPR), a signaling pathway that triggers a comprehensive remodeling of the endoplasmic reticulum (ER) and the biosynthetic pathway according to need. We discovered […]

Autophagy counterbalances endoplasmic reticulum expansion during the unfolded protein response

KEYWORDS: A1PiZ • cytoplasmto-vacuole targeting • electron microscopy • endoplasmic reticulum • ER-associated protein degradation • ER-selective branch of autophagy • ERcontaining autophagosome • green fluorescent protein • nuclear envelope • pre-autophagosomal structure • Sebastián Bernales • unfolded protein response

ABSTRACT: The protein folding capacity of the endoplasmic reticulum (ER) is regulated by the unfolded protein response (UPR). The UPR senses unfolded proteins in the ER lumen and transmits that information to the cell nucleus, where it drives a transcriptional program that is tailored to re-establish homeostasis. Using thin section electron microscopy, we found that […]

Eisosomes mark static sites of endocytosis

KEYWORDS: 2006 • Eisosomes • Endocytosis • eukaryotic cells • lipid clustering • Sebastián Bernales • signalling receptors

ABSTRACT: Endocytosis functions to recycle plasma membrane components, to regulate cell-surface expression of signalling receptors and to internalize nutrients in all eukaryotic cells. Internalization of proteins, lipids and other cargo can occur by one of several pathways that have different, but often overlapping, molecular requirements1–5. To mediate endocytosis, effectors assemble transiently underneath the plasma membrane, carry out the […]

Intracellular signaling by the unfolded protein response

KEYWORDS: endoplasmic reticulum stress • organelle homeostasis • protein folding • regulated mRNA splicing • Sebastián Bernales • signal transduction • translational control

ABSTRACT: The unfolded protein response (UPR) is an intracellular signaling pathway that is activated by the accumulation of unfolded proteins in the endoplasmic reticulum (ER). UPR activation triggers an extensive transcriptional response, which adjusts the ER protein folding capacity according to need. As such, the UPR constitutes a paradigm of an intracellular control mechanism that adjusts organelle abundance in response to […]