Referencia

PLoS Genet. 2011 Feb 10;7(2):e1001297

Autores

Esmeralda Parra-Peralbo y Joaquim Culí

Resumen

El aumento alarmante en la incidencia de la obesidad y la diabetes experimentado durante las últimas tres décadas hace necesario el estudio de los complejos mecanismos que regulan el almacenaje del aporte calórico sobrante en forma de grasa corporal. El uso de organismos modelo fácilmente manipulables a nivel genético, como Drosophila melanogaster, ha proporcionado importantes avances en este campo. En este trabajo hemos estudiado el mecanismo molecular que media la transferencia de lípidos neutros desde las lipoproteínas circulantes a los tejidos de Drosophila. Nuestro trabajo describe la función crucial de los receptores de lipoforinas (homólogos a los receptores de LDL, VLDL y ApoE de humanos) en la adquisición celular de lípidos neutros. Demostramos que el proceso de lipólisis ocurre extracelularmente de manera similar a como ocurre en los microcapilares de los mamíferos, sugiriendo un papel ancestral de las proteínas de la familia LDLR en el procesamiento extracelular de lipoproteínas.

Descripción

Lipids are constantly shuttled through the body to redistribute energy and metabolites between sites of absorption, storage and catabolism in a complex homeostatic equilibrium. In Drosophila, lipids are transported through the hemolymph in the form of lipoprotein particles, known as lipophorins. The mechanisms by which cells interact with circulating lipophorins and acquire their lipidic cargo are poorly understood. We have found that lipophorin receptor 1 and 2 (lpr1 and lpr2), two partially redundant genes belonging to the Low Density Lipoprotein Receptor (LDLR) family, are essential for the efficient uptake and accumulation of neutral lipids by oocytes and cells of the imaginal discs. Females lacking the lpr2 gene lay eggs with low lipid content and have reduced fertility,
revealing a central role for lpr2 in mediating Drosophila vitellogenesis. lpr1 and lpr2 are transcribed into multiple isoforms. Interestingly, only a subset of these isoforms containing a particular LDLR type A module mediate neutral lipid uptake. Expression of these isoforms induces the extracellular stabilization of lipophorins. Furthermore, our data indicates that endocytosis is not required to mediate the uptake of neutral lipids. These findings suggest a model where lipophorin receptors promote the extracellular lipolysis of lipophorins. This model is reminiscent of the lipolytic processing of triglyceride-rich lipoproteins that occurs at the mammalian capillary endothelium, suggesting an ancient role for LDLR-like proteins in this process.

Imagen artículo Julio

REFERENCIA DEL GRUPO E INVESTIGADOR
Esmeralda Parra-Peralbo ha realizado su tesis doctoral en el grupo dirigido por Joaquim Culi en el Centro Andaluz de Biología del Desarrollo, un centro mixto del CSIC y la UPO. Mediante aproximaciones genéticas y bioquímicas, estudiamos aspectos básicos del metabolismo de las lipoproteínas y sus receptores, utilizando la mosca Drosophila melanogaster como organismo modelo.

Descárgate este artículo aquí.
Más artículos en la revista SEBBM.

¿Acabas de publicar un artículo interesante?

Manda la referencia a través de nuestro formulario.  Límite de edad 32 años. Los artículos seleccionados serán destacados como artículos del mes y participarán en el Premio al mejor artículo de jóvenes de la SEBBM, que se entregará en el congreso de la SEBBM (inscripción y alojamiento gratuitos).

Otros "Artículos del mes"

Glucose restriction promotes osteocyte specification by activating a PGC-1α-dependent transcriptional program

03-06-2019

Osteocytes, the most abundant of bone cells, differentiate while they remain buried within the bone matrix. This encasement limits their access to nutrients and likely affects their differentiation, a process...

Leer más

ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements

01-05-2019

/Bacillus subtilis/ ParB forms multimeric networks involving non-specific DNA binding leading to DNA condensation. Previously, we found that an excess of the free C-terminal domain (CTD) of ParB impeded DNA...

Leer más

Therapeutic targeting of HER2-CB2R heteromers in HER2-positive breast cancer

01-04-2019

Although human epidermal growth factor receptor 2 (HER2)-targeted therapies have dramatically improved the clinical outcome of HER2-positive breast cancer patients, innate and acquired resistance remains an important clinical challenge. New...

Leer más

p73 regulates ependymal planar cell polarity by modulating actin and microtubule cytoskeleton

01-03-2019

Planar cell polarity (PCP) and intercellular junctional complexes establish tissue structure and coordinated behaviors across epithelial sheets. In multiciliated ependymal cells, rotational and translational PCP coordinate cilia beating and direct...

Leer más

β‐RA reduces DMQ/CoQ ratio and rescues the encephalopathic phenotype in Coq9R239X mice

01-02-2019

Coenzyme Q (CoQ) deficiency has been associated with primary defects in the CoQ biosynthetic pathway or to secondary events. In some cases, the exogenous CoQ supplementation has limited efficacy. In...

Leer más

Small molecule inhibits α-synuclein aggregation, disrupts amyloid fibrils, and prevents degeneration of dopaminergic neurons

02-01-2019

Parkinson's disease (PD) is characterized by a progressive loss of dopaminergic neurons, a process that current therapeutic approaches cannot prevent. In PD, the typical pathological hallmark is the accumulation of...

Leer más

Dynamic acetylation of cytosolic phosphoenolpyruvate carboxykinase toggles enzyme activity between gluconeogenic and anaplerotic reactions

01-12-2018

Cytosolic phosphoenolpyruvate carboxykinase (PCK1) is considered a gluconeogenic enzyme; however, its metabolic functions and regulatory mechanisms beyond gluconeogenesis are poorly understood. Here, we describe that dynamic acetylation of PCK1 interconverts...

Leer más

The Helicase PIF1 Facilitates Resection overSequences Prone to Forming G4 Structures

02-11-2018

DNA breaks are complex lesions that can be repaired either by non-homologous end joining (NHEJ) or by homologous recombination (HR). The decision between these two routes of DNA repair is...

Leer más

Preventing loss of mechanosensation by the nuclear membranes of alveolar cells reduces lung injury in mice during mechanical ventilation

01-10-2018

The nuclear membrane acts as a mechanosensor that drives cellular responses following changes in the extracellular environment. Mechanically ventilated lungs are exposed to an abnormally high mechanical load that may...

Leer más

Oxidative stress is tightly regulated by cytochrome c phosphorylation and respirasome factors in mitochondria

03-09-2018

Respiratory cytochrome c has been found to be phosphorylated at tyrosine 97 in the postischemic brain upon neuroprotective insulin treatment, but how such posttranslational modification affects mitochondrial metabolism is unclear...

Leer más

Socios Protectores