Welcome To Website IAS

Hot news
Achievement

Independence Award

- First Rank - Second Rank - Third Rank

Labour Award

- First Rank - Second Rank -Third Rank

National Award

 - Study on food stuff for animal(2005)

 - Study on rice breeding for export and domestic consumption(2005)

VIFOTEC Award

- Hybrid Maize by Single Cross V2002 (2003)

- Tomato Grafting to Manage Ralstonia Disease(2005)

- Cassava variety KM140(2010)

Centres
Website links
Vietnamese calendar
Library
Visitors summary
 Curently online :  76
 Total visitors :  7644538

p53 at the endoplasmic reticulum regulates apoptosis in a Ca2+-dependent manner
Sunday, 2015/02/15 | 05:33:48

Carlotta Giorgi, Massimo Bonora, Giovanni Sorrentino, Sonia Missiroli, Federica Poletti, Jan M. Suski, Fabian Galindo Ramirez, Rosario Rizzuto, Francesco Di Virgilio, Ester Zito, Pier Paolo Pandolfi, Mariusz R. Wieckowski, Fabio Mammano, Giannino Del Sal, and Paolo Pinton

 

Significance

Accumulating evidence has underscored the role of cytosolic p53 in promoting cell death. Different reports have revealed that p53 participates in apoptosis induction by acting directly at mitochondria. However, because p53 can mediate apoptosis without its DNA-binding domain (the domain proposed to be fundamental for the targeting of p53 to mitochondria), the mitochondrial localization of p53 is likely not the only transcription-independent mechanism by which p53 promotes apoptosis. Here we demonstrate that p53 at the endoplasmic reticulum (ER) and at mitochondria-associated membranes, interacting with sarco/ER Ca2+-ATPase pumps, modulates ER–mitochondria cross-talk and, in turn, Ca2+-dependent apoptosis.

Abstract

The tumor suppressor p53 is a key protein in preventing cell transformation and tumor progression. Activated by a variety of stimuli, p53 regulates cell-cycle arrest and apoptosis. Along with its well-documented transcriptional control over cell-death programs within the nucleus, p53 exerts crucial although still poorly understood functions in the cytoplasm, directly modulating the apoptotic response at the mitochondrial level. Calcium (Ca2+) transfer between the endoplasmic reticulum (ER) and mitochondria represents a critical signal in the induction of apoptosis. However, the mechanism controlling this flux in response to stress stimuli remains largely unknown. Here we show that, in the cytoplasm, WT p53 localizes at the ER and at specialized contact domains between the ER and mitochondria (mitochondria-associated membranes). We demonstrate that, upon stress stimuli, WT p53 accumulates at these sites and modulates Ca2+ homeostasis. Mechanistically, upon activation, WT p53 directly binds to the sarco/ER Ca2+-ATPase (SERCA) pump at the ER, changing its oxidative state and thus leading to an increased Ca2+ load, followed by an enhanced transfer to mitochondria. The consequent mitochondrial Ca2+ overload causes in turn alterations in the morphology of this organelle and induction of apoptosis. Pharmacological inactivation of WT p53 or naturally occurring p53 missense mutants inhibits SERCA pump activity at the ER, leading to a reduction of the Ca2+ signaling from the ER to mitochondria. These findings define a critical nonnuclear function of p53 in regulating Ca2+ signal-dependent apoptosis.

 

See: http://www.pnas.org/content/112/6/1779.abstract.html?etoc

PNAS February 10, 2015 vol. 112 no. 6 1779-1784

 

Fig. 1.

Fig. 1. p53 localizes at the ER and MAMs. (AC) Detection of p53 by immunoblotting in HCT-116 p53+/+ fractions. (A) p53 localization in untreated condition (UNT). Accumulation of p53 at the ER and MAMs in HCT-116 p53+/+ cells after adriamycin (ADRIA) induction (1 μM, 6 h) (B) or after H2O2 treatment (500 μM, 6 h) (C). (DF) Colocalization of p53 (red) and Sec61-GFP (used as ER marker; green) in p53+/+ MEFs under untreated conditions (UNT) (D) and after ADRIA (E) or H2O2 (F). (Insets) A higher magnification of the images is presented. (G) p53 activation increased its ER colocalization. Colocalization of p53 and ER in p53+/+ MEFs quantified as the proportion of total ER marker overlapping the p53 signal (by Mander’s coefficient colocalization method). To allow for a better appreciation of colocalization of p53 with the ER, a cytoplasmic portion was selected and the contrast was increased. Bars, SEM; *P < 0.05.

Back      Print      View: 1078

[ Other News ]___________________________________________________
  • Genome-wide analysis of autophagy-associated genes in foxtail millet (Setaria italica L.) and characterization of the function of SiATG8a in conferring tolerance to nitrogen starvation in rice.
  • Arabidopsis small nucleolar RNA monitors the efficient pre-rRNA processing during ribosome biogenesis
  • XA21-specific induction of stress-related genes following Xanthomonas infection of detached rice leaves.
  • Reducing the Use of Pesticides with Site-Specific Application: The Chemical Control of Rhizoctonia solani as a Case of Study for the Management of Soil-Borne Diseases
  • OsJRL, a rice jacalin-related mannose-binding lectin gene, enhances Escherichia coli viability under high-salinity stress and improves salinity tolerance of rice.
  • Production of lipopeptide biosurfactants by Bacillus atrophaeus 5-2a and their potential use in microbial enhanced oil recovery.
  • GhABF2, a bZIP transcription factor, confers drought and salinity tolerance in cotton (Gossypium hirsutum L.).
  • Resilience of cassava (Manihot esculenta Crantz) to salinity: implications for food security in low-lying regions.
  • Cellulose synthase complexes act in a concerted fashion to synthesize highly aggregated cellulose in secondary cell walls of plants
  • No adverse effects of transgenic maize on population dynamics of endophytic Bacillus subtilis strain B916-gfp
  • Identification and expression analysis of OsLPR family revealed the potential roles of OsLPR3 and 5 in maintaining phosphate homeostasis in rice
  • Functional analysis of molecular interactions in synthetic auxin response circuits
  • Titanium dioxide nanoparticles strongly impact soil microbial function by affecting archaeal nitrifiers.
  • Inducible Expression of the De-Novo Designed Antimicrobial Peptide SP1-1 in Tomato Confers Resistance to Xanthomonas campestris pv. vesicatoria.
  • Toward combined delignification and saccharification of wheat straw by a laccase-containing designer cellulosome
  • SNP-based discovery of salinity-tolerant QTLs in a bi-parental population of rice (Oryza sativa)
  • Pinpointing genes underlying the quantitative trait loci for root-knot nematode resistance in palaeopolyploid soybean by whole genome resequencing.
  • Transcriptome- Assisted Label-Free Quantitative Proteomics Analysis Reveals Novel Insights into Piper nigrum -Phytophthora capsici Phytopathosystem.
  • Brassinosteroids participate in the control of basal and acquired freezing tolerance of plants
  • Rapid hyperosmotic-induced Ca2+ responses in Arabidopsis thaliana exhibit sensory potentiation and involvement of plastidial KEA transporters

 

Designed & Powered by WEBSO CO.,LTD