Browsing by Author "Cancino, Jorge"
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- ItemAntibody to AP1B adaptor blocks biosynthetic and recycling routes of basolateral proteins at recycling endosomes(AMER SOC CELL BIOLOGY, 2007) Cancino, Jorge; Torrealba, Carolina; Soza, Andrea; Yuseff, Maria Isabel; Gravotta, Diego; Henklein, Peter; Rodriguez Boulan, Enrique; Gonzalez, AlfonsoThe epithelial-specific adaptor AP1B sorts basolateral plasma membrane (PM) proteins in both biosynthetic and recycling routes, but the site where it carries out this function remains incompletely defined. Here, we have investigated this topic in Fischer rat thyroid (FRT) epithelial cells using an antibody against the medium subunit mu 1B. This antibody was suitable for immunofluorescence and blocked the function of AP1B in these cells. The antibody blocked the basolateral recycling of two basolateral PM markers, Transferrin receptor (TfR) and LDL receptor (LDLR), in a perinuclear compartment with marker and functional characteristics of recycling endosomes (RE). Live imaging experiments demonstrated that in the presence of the antibody two newly synthesized GFP-tagged basolateral proteins (vesicular stomatitis virus G [VSVG] protein and TfR) exited the trans-Golgi network (TGN) normally but became blocked at the RE within 3-5 min. By contrast, the antibody did not block trafficking of green fluorescent protein (GFP)-LDLR from the TGN to the PM but stopped its recycling after internalization into RE in similar to 45 min. Our experiments conclusively demonstrate that 1) AP1B functions exclusively at RE; 2) TGN-to-RE transport is very fast and selective and is mediated by adaptors different from AP1B; and 3) the TGN and AP1B-containing RE cooperate in biosynthetic basolateral sorting.
- ItemBasal Serum Cortisol and Testosterone/Cortisol Ratio Are Related to Rate of Na+ Lost During Exercise in Elite Soccer Players(2019) Castro Sepúlveda, Mauricio; Cancino, Jorge; Fernández Verdejo, Rodrigo; Pérez Luco, Cristián; Jannas Vela, Sebastian; Ramírez Campillo, Rodrigo; Del Coso, Juan; Zbinden Foncea, Hermann
- ItemEstimation of ventilatory thresholds during exercise using respiratory wearable sensors(2024) Contreras Briceño, Felipe; Cancino, Jorge; Espinosa Ramírez, Maximiliano Andrés; Fernández, Gonzalo; Johnson, Vader; Lopez Hurtado Daniel EduardoVentilatory thresholds (VTs) are key physiological parameters used to evaluate physical performanceand determine aerobic and anaerobic transitions during exercise. Current assessment of theseparameters requires ergospirometry, limiting evaluation to laboratory or clinical settings. In this work,we introduce a wearable respiratory system that continuously tracks breathing during exercise andestimates VTs during ramp tests. We validate the respiratory rate and VTs predictions in 17 healthyadults using ergospirometry analysis. In addition, we use the wearable system to evaluate VTs in 107recreational athletes during ramp tests outside the laboratory and show that the mean populationvalues agree with physiological variables traditionally used to exercise prescription. We envision thatrespiratory wearables can be useful in determining aerobic and anaerobic parameters with promisingapplications in health telemonitoring and human performance
- ItemKDEL receptor regulates secretion by lysosome relocation- and autophagy-dependent modulation of lipid-droplet turnover(2019) Tapia, Diego; Zamora, Constanza; Espinoza, Javier; Rizzo, Riccardo; González Cárdenas, Alexis; Fuentes Peña, Danitza Natalia; Hernández, Sergio; Cavieres, Viviana A.; Guzmán, Fanny; Arriagada, Gloria; Yuseff Sepúlveda, María Isabel; Mardones, Gonzalo A.; Burgos , Patricia V.; Luini, Alberto; González, Alfonso; Cancino, Jorge; Jiménez, Tomás; Soza Gajardo, Andrea
- ItemPex3p-Dependent Peroxisomal Biogenesis Initiates in the Endoplasmic Reticulum of Human Fibroblasts(WILEY-BLACKWELL, 2009) Toro, Andres A.; Araya, Claudia A.; Cordova, Gonzalo J.; Arredondo, Cristian A.; Cardenas, Hugo G.; Moreno, Regina E.; Venegas, Alejandro; Koenig, Cecilia S.; Cancino, Jorge; Gonzalez, Alfonso; Santos, Manuel J.The mechanisms of peroxisomal biogenesis remain incompletely understood, specially regarding the role of the endoplasmic reticulum (ER) in human cells, where genetic disorders of peroxisome biogenesis lead to Zellweger syndrome (ZS). The Pex3p peroxisomal membrane protein (PMP) required for early steps of peroxisome biogenesis has been detected in the ER in yeast but not in mammalian cells. Here, we show that Pex3p-GFP expressed in a new ZS cell line (MR), which lacks peroxisomes due to a mutation in the PEX3 gene, localizes first in the ER and subsequently in newly formed peroxisomes. Pex3p bearing an artificial N-glycosylation site shows an electrophoretic shift indicative of ER targeting while en route to preformed peroxisomes in normal fibroblast. A signal peptide that forces its entry into the ER does not eliminate its capability to drive peroxisome biogenesis in ZS cells. Thus, Pex3p is able to drive peroxisome biogenesis from the ER and its ER pathway is not privative of ZS cells. Cross-expression experiments of Pex3p in GM623 cells lacking Pex16p or Pex16p in MR cells lacking Pex3p, showed evidence that Pex3p requires Pex16p for ER location but: is dispensable for the ER location of Pex16p. These results indicate that Pex3p follows the ER-to-peroxisomal route in mammalian cells and provides new clues to understand its function. J. Cell. Biochem. 107: 10831096, 2009. (C) 2009 Wiley-Liss, Inc.
- ItemPhosphatidic Acid Induces Ligand-independent Epidermal Growth Factor Receptor Endocytic Traffic through PDE4 Activation(AMER SOC CELL BIOLOGY, 2010) Norambuena, Andres; Metz, Claudia; Jung, Juan E.; Silva, Antonia; Otero, Carolina; Cancino, Jorge; Retamal, Claudio; Valenzuela, Juan C.; Soza, Andrea; Gonzalez, AlfonsoEndocytosis modulates EGFR function by compartmentalizing and attenuating or enhancing its ligand-induced signaling. Here we show that it can also control the cell surface versus intracellular distribution of empty/inactive EGFR. Our previous observation that PKA inhibitors induce EGFR internalization prompted us to test phosphatidic acid (PA) generated by phospholipase D (PLD) as an endogenous down-regulator of PKA activity, which activates rolipram-sensitive type 4 phosphodiesterases (PDE4) that degrade cAMP. We found that inhibition of PA hydrolysis by propranolol, in the absence of ligand, provokes internalization of inactive (neither tyrosine-phosphorylated nor ubiquitinated) EGFR, accompanied by a transient increase in PA levels and PDE4s activity. This EGFR internalization is mimicked by PA micelles and is strongly counteracted by PLD2 silencing, rolipram or forskolin treatment, and PKA overexpression. Accelerated EGFR endocytosis seems to be mediated by clathrin-dependent and -independent pathways, leading to receptor accumulation in juxtanuclear recycling endosomes, also due to a decreased recycling. Internalized EGFR can remain intracellular without degradation for several hours or return rapidly to the cell surface upon discontinuation of the stimulus. This novel regulatory mechanism of EGFR, also novel function of signaling PA, can transmodulate receptor accessibility in response to heterologous stimuli.