Referencia

Plant Cell 25: 4183-4194.

Autores

Pablo Pulido, Gabriela Toledo-Ortiz, Michael A. Phillips, Louwrance P. Wright, y Manuel Rodríguez-Concepción.

Resumen

Plastids provide plants with metabolic pathways that are unique among eukaryotes, including the methylerythritol 4-phosphate pathway for the production of isoprenoids essential for photosynthesis and plant growth. Here, we show that the first enzyme of the pathway, deoxyxylulose 5-phosphate synthase (DXS), interacts with the J-protein J20 in Arabidopsis thaliana. J-proteins typically act as adaptors that provide substrate specificity to heat shock protein 70 (Hsp70), a molecular chaperone. Immunoprecipitation experiments showed that J20 and DXS are found together in vivo and confirmed the presence of Hsp70 chaperones in DXS complexes. Mutants defective in J20 activity accumulated significantly increased levels of DXS protein (but no transcripts) and displayed reduced levels of DXS enzyme activity, indicating that loss of J20 function causes posttranscriptional accumulation of DXS in an inactive form. Furthermore, J20 promotes degradation of DXS following a heat shock. Together, our data indicate that J20 might identify unfolded or misfolded (damaged) forms of DXS and target them to the Hsp70 system for proper folding under normal conditions or degradation upon stress.

Descripción

DXS es el primer enzima de la ruta de biosíntesis de isoprenoides chloroplastídicos. En este trabajo describimos como la cochaperona J20 interacciona específicamente con DXS facilitando su correcto plegamiento por la chaperona molecular Hsp70. DXS se acumula de manera inactiva en el mutante para J20 mientras que la sobreexpresión de J20-GFP provoca una disminución de los niveles de DXS. En conjunto, nuestros datos indican que el sistema J20/Hsp70 participa tanto en el plegamiento como en la degradación de DXS inactiva.

grupo

REFERENCIA DEL GRUPO INVESTIGADOR

Nuestro grupo forma parte del programa de Metabolismo e Ingeniería Metabólica del CRAG, Barcelona (www.cragenomica.es). Su interés principal es entender como los cloroplastos de las células vegetales regulan la biosíntesis de isoprenoides, que son metabolitos esenciales para la fotosíntesis y el desarrollo de la planta. Mediante abordajes de genética, bioquímica, y biología molecular, en los últimos años hemos descubierto varios mecanismos post-transcripcionales que permiten a los cloroplastos controlar finamente los niveles y la actividad de enzimas clave de la biosíntesis de isoprenoides. Nuestro trabajo también abarca la regulación transcripcional de genes biosintéticos en plantas y el estudio de enzimas alternativos en sistemas bacterianos.

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

Did you publish an interesting article recently?

Send it through our application form and we will contact you. Age limit: 32.

The selected articles will participate at the Award to the best article of young people of the SEBBM which will be given during SEBBM conference, that will take place at Spain (free registration, travel and accommodation).

More articles of the month

Sticholysin, Sphingomyelin, and Cholesterol: A Closer Look at a Tripartite Interaction

01-08-2019

Actinoporins are a group of soluble toxic proteins that bind to membranes containing sphingomyelin (SM) and oli- gomerize to form pores. Sticholysin II (StnII) is a member of the actinoporin...

Read more

Astrocytic mitochondrial ROS modulate brain metabolism and mouse behaviour

01-07-2019

To satisfy its high energetic demand, the brain depends on the metabolic cooperation of various cell types. For example, astrocytic-derived lactate sustains memory consolidation by serving both as an oxidizable...

Read more

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...

Read more

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...

Read more

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...

Read more

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...

Read more

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...

Read more

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...

Read more

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...

Read more

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...

Read more

Protector Members