scholarly journals DNAJ Protein

2020 ◽  
Author(s):  
Keyword(s):  
Dnaj Protein

scholarly journals Extracellular vesicle budding is inhibited by redundant regulators of TAT-5 flippase localization and phospholipid asymmetry

2018 ◽  
Vol 115 (6) ◽  
pp. E1127-E1136 ◽  
Author(s):  
Katharina B. Beer ◽  
Jennifer Rivas-Castillo ◽  
Kenneth Kuhn ◽  
Gholamreza Fazeli ◽  
Birgit Karmann ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Extracellular Vesicle ◽  
Endosomal Trafficking ◽  
Vesicle Budding ◽  
Sorting Nexins ◽  
Dnaj Protein ◽  
Membrane Budding ◽  
Pleiotropic Functions

Cells release extracellular vesicles (EVs) that mediate intercellular communication and repair damaged membranes. Despite the pleiotropic functions of EVs in vitro, their in vivo function is debated, largely because it is unclear how to induce or inhibit their formation. In particular, the mechanisms of EV release by plasma membrane budding or ectocytosis are poorly understood. We previously showed that TAT-5 phospholipid flippase activity maintains the asymmetric localization of the lipid phosphatidylethanolamine (PE) in the plasma membrane and inhibits EV budding by ectocytosis in Caenorhabditis elegans. However, no proteins that inhibit ectocytosis upstream of TAT-5 were known. Here, we identify TAT-5 regulators associated with retrograde endosomal recycling: PI3Kinase VPS-34, Beclin1 homolog BEC-1, DnaJ protein RME-8, and the uncharacterized Dopey homolog PAD-1. PI3Kinase, RME-8, and semiredundant sorting nexins are required for the plasma membrane localization of TAT-5, which is important to maintain PE asymmetry and inhibit EV release. PAD-1 does not directly regulate TAT-5 localization, but is required for the lipid flipping activity of TAT-5. PAD-1 also has roles in endosomal trafficking with the GEF-like protein MON-2, which regulates PE asymmetry and EV release redundantly with sorting nexins independent of the core retromer. Thus, in addition to uncovering redundant intracellular trafficking pathways, our study identifies additional proteins that regulate EV release. This work pinpoints TAT-5 and PE as key regulators of plasma membrane budding, further supporting the model that PE externalization drives ectocytosis.

scholarly journals A fungal effector targets a heat shock–dynamin protein complex to modulate mitochondrial dynamics and reduce plant immunity

2020 ◽  
Vol 6 (48) ◽  
pp. eabb7719
Author(s):  
Guojuan Xu ◽  
Xionghui Zhong ◽  
Yanlong Shi ◽  
Zhuo Liu ◽  
Nan Jiang ◽  
...  
Keyword(s):  
Transgenic Rice ◽  
Protein Complex ◽  
Fungal Pathogen ◽  
Mitochondrial Dynamics ◽  
Plant Immunity ◽  
Mitochondrial Fission ◽  
Plant Cells ◽  
Related Protein ◽  
Dnaj Protein ◽  
Enhanced Resistance

Mitochondria are essential for animal and plant immunity. Here, we report that the effector MoCDIP4 of the fungal pathogen Magnaporthe oryzae targets the mitochondria-associated OsDjA9-OsDRP1E protein complex to reduce rice immunity. The DnaJ protein OsDjA9 interacts with the dynamin-related protein OsDRP1E and promotes the degradation of OsDRP1E, which functions in mitochondrial fission. By contrast, MoCDIP4 binds OsDjA9 to compete with OsDRP1E, resulting in OsDRP1E accumulation. Knockout of OsDjA9 or overexpression of OsDRP1E or MoCDIP4 in transgenic rice results in shortened mitochondria and enhanced susceptibility to M. oryzae. Overexpression of OsDjA9 or knockout of OsDRP1E in transgenic rice, in contrast, leads to elongated mitochondria and enhanced resistance to M. oryzae. Our study therefore reveals a previously unidentified pathogen-infection strategy in which the pathogen delivers an effector into plant cells to target an HSP40-DRP complex; the targeting leads to the perturbation of mitochondrial dynamics, thereby inhibiting mitochondria-mediated plant immunity.

scholarly journals A novel variant of the human mitochondrial DnaJ protein, Tid1, associates with a human disease exhibiting developmental delay and polyneuropathy

2019 ◽  
Vol 27 (7) ◽  
pp. 1072-1080 ◽  
Author(s):  
Malay Patra ◽  
Celeste Weiss ◽  
Bassam Abu-Libdeh ◽  
Motee Ashhab ◽  
Shadi Abuzer ◽  
...  
Keyword(s):  
Developmental Delay ◽  
Human Disease ◽  
Dnaj Protein ◽  
Novel Variant

scholarly journals Novel DnaJ Protein Facilitates Thermotolerance of Transgenic Tomatoes

2019 ◽  
Vol 20 (2) ◽  
pp. 367 ◽  
Author(s):  
Guodong Wang ◽  
Guohua Cai ◽  
Na Xu ◽  
Litao Zhang ◽  
Xiuling Sun ◽  
...  
Keyword(s):  
Heat Stress ◽  
D1 Protein ◽  
Heat Sensitivity ◽  
Yeast Two Hybrid ◽  
Protein Levels ◽  
Dnaj Protein ◽  
Yeast Two Hybrid System ◽  
Ros Accumulation ◽  
Transgenic Tomatoes ◽  
Two Hybrid

DnaJ proteins, which are molecular chaperones that are widely present in plants, can respond to various environmental stresses. At present, the function of DnaJ proteins was studied in many plant species, but only a few studies were conducted in tomato. Here, we examined the functions of a novel tomato (Solanum lycopersicum) DnaJ protein (SlDnaJ20) in heat tolerance using sense and antisense transgenic tomatoes. Transient conversion assays of Arabidopsis protoplasts showed that SlDnaJ20 was targeted to chloroplasts. Expression analysis showed that SlDnaJ20 expression was induced by chilling, NaCl, polyethylene glycol, and H2O2, especially via heat stress. Under heat stress, sense plants showed higher fresh weights, chlorophyll content, fluorescence (Fv/Fm), and D1 protein levels, and a lower accumulation of reactive oxygen species (ROS) than antisense plants. These results suggest that SlDnaJ20 overexpression can reduce the photoinhibition of photosystem II (PSII) by relieving ROS accumulation. Moreover, higher expression levels of HsfA1 and HsfB1 were observed under heat stress in sense plants, indicating that SlDnaJ20 overexpression contributes to HSF expression. The yeast two-hybrid system proved that SlDnaJ20 can interact with the chloroplast heat-shock protein 70. Our results indicate that SlDnaJ20 overexpression enhances the thermotolerance of transgenic tomatoes, whereas suppression of SlDnaJ20 increases the heat sensitivity of transgenic tomatoes.

Identification and characterization of rDJL, a novel member of the DnaJ protein family, in rat testis

FEBS Letters ◽  
2005 ◽  
Vol 579 (25) ◽  
pp. 5734-5740 ◽  
Author(s):  
Chunbo Yang ◽  
Shiying Miao ◽  
Shudong Zong ◽  
Samuel S. Koide ◽  
Linfang Wang
Keyword(s):  
Protein Family ◽  
Rat Testis ◽  
Dnaj Protein ◽  
Identification And Characterization

scholarly journals Tid1, a Cochaperone of the Heat Shock 70 Protein and the Mammalian Counterpart of the Drosophila Tumor Suppressor l(2)tid, Is Critical for Early Embryonic Development and Cell Survival

2004 ◽  
Vol 24 (6) ◽  
pp. 2226-2236 ◽  
Author(s):  
Jeng-Fan Lo ◽  
Masaaki Hayashi ◽  
Sung Woo-Kim ◽  
Bin Tian ◽  
Jing-Feng Huang ◽  
...  
Keyword(s):  
Heat Shock ◽  
Tumor Suppressor ◽  
Cell Survival ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Ectopic Expression ◽  
Conditional Knockout ◽  
Dnaj Protein ◽  
J Domain ◽  
Mammalian Counterpart

ABSTRACT Tid1 is the mammalian counterpart of the Drosophila tumor suppressor Tid56 and is also a DnaJ protein containing a conserved J domain through which it interacts with the heat shock protein 70 (Hsp70) family of chaperone proteins. We generated a Tid1 conditional mutation in mice, and the subsequent global removal of the Tid1 protein was achieved by crossing these conditional knockout mice with general deletor mice. No Tid1−/− embryos were detected as early as embryonic day 7.5 (E7.5). Nonetheless, Tid1-deficient blastocysts were viable, hatched, formed an inner cell mass and trophectoderm, and implanted (E4.5), suggesting that the homozygous mutant embryos die between E4.5 and E7.5. To assess the function of Tid1 in embryonic cells, mouse embryonic fibroblasts with the homologous Tid1 floxed allele were produced. Tid1 removal in these cells led to massive cell death. The death of Tid1-deficient cells could be rescued by ectopic expression of wild-type Tid1 but not by expression of the Tid1 protein that had a mutated J domain and was thus incapable of binding to Hsp70. We propose that Tid1 is critical for early mammalian development, most likely for its function in sustaining embryonic-cell survival, which requires its association with Hsp70.

scholarly journals Reconstitution of aMycobacterium tuberculosisproteostasis network highlights essential cofactor interactions with chaperone DnaK

2016 ◽  
Vol 113 (49) ◽  
pp. E7947-E7956 ◽  
Author(s):  
Tania J. Lupoli ◽  
Allison Fay ◽  
Carolina Adura ◽  
Michael S. Glickman ◽  
Carl F. Nathan
Keyword(s):  
Protein Interactions ◽  
Drug Targets ◽  
Small Heat Shock Protein ◽  
Protein Aggregates ◽  
Dnaj Protein ◽  
Chaperone Protein ◽  
Chaperone Dnak ◽  
Molecular Machinery ◽  
Host Infection ◽  
Potential Drug Targets

During host infection,Mycobacterium tuberculosis(Mtb) encounters several types of stress that impair protein integrity, including reactive oxygen and nitrogen species and chemotherapy. The resulting protein aggregates can be resolved or degraded by molecular machinery conserved from bacteria to eukaryotes. Eukaryotic Hsp104/Hsp70 and their bacterial homologs ClpB/DnaK are ATP-powered chaperones that restore toxic protein aggregates to a native folded state. DnaK is essential inMycobacterium smegmatis, and ClpB is involved in asymmetrically distributing damaged proteins during cell division as a mechanism of survival in Mtb, commending both proteins as potential drug targets. However, their molecular partners in protein reactivation have not been characterized in mycobacteria. Here, we reconstituted the activities of the Mtb ClpB/DnaK bichaperone system with the cofactors DnaJ1, DnaJ2, and GrpE and the small heat shock protein Hsp20. We found that DnaJ1 and DnaJ2 activate the ATPase activity of DnaK differently. A point mutation in the highly conserved HPD motif of the DnaJ proteins abrogates their ability to activate DnaK, although the DnaJ2 mutant still binds to DnaK. The purified Mtb ClpB/DnaK system reactivated a heat-denatured model substrate, but the DnaJ HPD mutants inhibited the reaction. Finally, either DnaJ1 or DnaJ2 is required for mycobacterial viability, as is the DnaK-activating activity of a DnaJ protein. These studies lay the groundwork for strategies to target essential chaperone–protein interactions in Mtb, the leading cause of death from a bacterial infection.

scholarly journals HTLV-1 Tax-associated hTid-1, a Human DnaJ Protein, Is a Repressor of IκB Kinase β Subunit

2002 ◽  
Vol 277 (23) ◽  
pp. 20605-20610 ◽  
Author(s):  
Hua Cheng ◽  
Carlo Cenciarelli ◽  
Mingyuan Tao ◽  
Wade P. Parks ◽  
Cecilia Cheng-Mayer
Keyword(s):  
Β Subunit ◽  
Dnaj Protein ◽  
Iκb Kinase
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