scholarly journals The Matrix Protein hnRNP U Is Required for Chromosomal Localization of Xist RNA

2010 ◽  
Vol 19 (3) ◽  
pp. 469-476 ◽  
Author(s):  
Yuko Hasegawa ◽  
Neil Brockdorff ◽  
Shinji Kawano ◽  
Kimiko Tsutui ◽  
Ken Tsutui ◽  
...  
Keyword(s):  
Matrix Protein ◽  
Chromosomal Localization ◽  
Xist Rna ◽  
Hnrnp U ◽  
The Matrix

Periodic Structure in the Matrix Protein of an Insect Virus

1982 ◽  
Vol 40 ◽  
pp. 302-303
Author(s):  
H.M. Mazzone ◽  
W.F. Engler ◽  
R. Zerillo ◽  
G.F. Bahr
Keyword(s):  
Inclusion Body ◽  
Periodic Structure ◽  
Matrix Protein ◽  
Malacosoma Disstria ◽  
Insect Virus ◽  
Virus Particles ◽  
The Matrix ◽  
Nucleopolyhedrosis Virus

The nucleopolyhedrosis virus (NPV) of the forest tent cater - pillar (Malacosoma disstria Hubner) has been analyzed in our laboratories. As a representative of the Baculovirus class, the NPV has virus particles enclosed with in a proteinaceous structure, the inclusion body.

scholarly journals Characterization of Mmp37p, aSaccharomyces cerevisiaeMitochondrial Matrix Protein with a Role in Mitochondrial Protein Import

2006 ◽  
Vol 17 (9) ◽  
pp. 4051-4062 ◽  
Author(s):  
Michelle R. Gallas ◽  
Mary K. Dienhart ◽  
Rosemary A. Stuart ◽  
Roy M. Long
Keyword(s):  
Matrix Protein ◽  
Protein Import ◽  
Mitochondrial Protein ◽  
Temperature Sensitive ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
Close Proximity ◽  
The Matrix ◽  
Targeting Signal

Many mitochondrial proteins are encoded by nuclear genes and after translation in the cytoplasm are imported via translocases in the outer and inner membranes, the TOM and TIM complexes, respectively. Here, we report the characterization of the mitochondrial protein, Mmp37p (YGR046w) and demonstrate its involvement in the process of protein import into mitochondria. Haploid cells deleted of MMP37 are viable but display a temperature-sensitive growth phenotype and are inviable in the absence of mitochondrial DNA. Mmp37p is located in the mitochondrial matrix where it is peripherally associated with the inner membrane. We show that Mmp37p has a role in the translocation of proteins across the mitochondrial inner membrane via the TIM23-PAM complex and further demonstrate that substrates containing a tightly folded domain in close proximity to their mitochondrial targeting sequences display a particular dependency on Mmp37p for mitochondrial import. Prior unfolding of the preprotein, or extension of the region between the targeting signal and the tightly folded domain, relieves their dependency for Mmp37p. Furthermore, evidence is presented to show that Mmp37 may affect the assembly state of the TIM23 complex. On the basis of these findings, we hypothesize that the presence of Mmp37p enhances the early stages of the TIM23 matrix import pathway to ensure engagement of incoming preproteins with the mtHsp70p/PAM complex, a step that is necessary to drive the unfolding and complete translocation of the preprotein into the matrix.

scholarly journals Mitochondrial Lon protease is a gatekeeper for proteins newly imported into the matrix

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yuichi Matsushima ◽  
Kazuya Takahashi ◽  
Song Yue ◽  
Yuki Fujiyoshi ◽  
Hideaki Yoshioka ◽  
...  
Keyword(s):  
Protease Activity ◽  
Matrix Protein ◽  
Protein Import ◽  
Atp Hydrolysis ◽  
Lon Protease ◽  
Mitochondrial Matrix ◽  
The Matrix ◽  
Specific Proteins ◽  
Aggregation Activity ◽  
Hydrolysis Activity

AbstractHuman ATP-dependent Lon protease (LONP1) forms homohexameric, ring-shaped complexes. Depletion of LONP1 causes aggregation of a broad range of proteins in the mitochondrial matrix and decreases the levels of their soluble forms. The ATP hydrolysis activity, but not protease activity, of LONP1 is critical for its chaperone-like anti-aggregation activity. LONP1 forms a complex with the import machinery and an incoming protein, and protein aggregation is linked with matrix protein import. LONP1 also contributes to the degradation of imported, aberrant, unprocessed proteins using its protease activity. Taken together, our results show that LONP1 functions as a gatekeeper for specific proteins imported into the mitochondrial matrix.

scholarly journals Homocysteine and Hypertension in Diabetes: Does PPARγHave a Regulatory Role?

PPAR Research ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Utpal Sen ◽  
Suresh C. Tyagi
Keyword(s):  
Matrix Protein ◽  
Vascular Endothelial Cells ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Extracellular Matrix Protein ◽  
Matrix Remodeling ◽  
Renal Volume ◽  
Vascular Effects ◽  
Beneficial Effects ◽  
The Matrix ◽  
Volume Retention

Dysfunction of macro- and microvessels is a major cause of morbidity and mortality in patients with cardio-renovascular diseases such as atherosclerosis, hypertension, and diabetes. Renal failure and impairment of renal function due to vasoconstriction of the glomerular arteriole in diabetic nephropathy leads to renal volume retention and increase in plasma homocysteine level. Homocysteine, which is a nonprotein amino acid, at elevated levels is an independent cardio-renovascular risk factor. Homocysteine induces oxidative injury of vascular endothelial cells, involved in matrix remodeling through modulation of the matrix metalloproteinase (MMP)/tissue inhibitor of metalloproteinase (TIMP) axis, and increased formation and accumulation of extracellular matrix protein, such as collagen. In heart this leads to increased endothelial-myocyte uncoupling resulting in diastolic dysfunction and hypertension. In the kidney, increased matrix accumulation in the glomerulus causes glomerulosclerosis resulting in hypofiltration, increased renal volume retention, and hypertension. PPARγagonist reduces tissue homocysteine levels and is reported to ameliorate homocysteine-induced deleterious vascular effects in diabetes. This review, in light of current information, focuses on the beneficial effects of PPARγagonist in homocysteine-associated hypertension and vascular remodeling in diabetes.

scholarly journals The Matrix Protein of Nipah Virus Targets the E3-Ubiquitin Ligase TRIM6 to Inhibit the IKKε Kinase-Mediated Type-I IFN Antiviral Response

2016 ◽  
Vol 12 (9) ◽  
pp. e1005880 ◽  
Author(s):  
Preeti Bharaj ◽  
Yao E. Wang ◽  
Brian E. Dawes ◽  
Tatyana E. Yun ◽  
Arnold Park ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Matrix Protein ◽  
Nipah Virus ◽  
E3 Ubiquitin Ligase ◽  
Antiviral Response ◽  
Type I ◽  
Type I Ifn ◽  
The Matrix

scholarly journals Tracking the Fate of Genetically Distinct Vesicular Stomatitis Virus Matrix Proteins Highlights the Role for Late Domains in Assembly

2015 ◽  
Vol 89 (23) ◽  
pp. 11750-11760 ◽  
Author(s):  
Timothy K. Soh ◽  
Sean P. J. Whelan
Keyword(s):  
Plasma Membrane ◽  
Vesicular Stomatitis Virus ◽  
Matrix Protein ◽  
Fluorescent Proteins ◽  
Endosomal Sorting ◽  
Escrt Machinery ◽  
Viral Particles ◽  
The Matrix ◽  
Vesicular Stomatitis ◽  
Late Domains

ABSTRACTVesicular stomatitis virus (VSV) assembly requires condensation of the viral ribonucleoprotein (RNP) core with the matrix protein (M) during budding from the plasma membrane. The RNP core comprises the negative-sense genomic RNA completely coated by the nucleocapsid protein (N) and associated by a phosphoprotein (P) with the large polymerase protein (L). To study the assembly of single viral particles, we tagged M and P with fluorescent proteins. We selected from a library of viruses with insertions in the M gene a replication-competent virus containing a fluorescent M and combined that with our previously described virus containing fluorescent P. Virus particles containing those fusions maintained the same bullet shape appearance as wild-type VSV but had a modest increase in particle length, reflecting the increased genome size. Imaging of the released particles revealed a variation in the amount of M and P assembled into the virions, consistent with a flexible packaging mechanism. We used the recombinants to further study the importance of the late domains in M, which serve to recruit the endosomal sorting complex required for transport (ESCRT) machinery during budding. Mutations in late domains resulted in the accumulation of virions that failed to pinch off from the plasma membrane. Imaging of single virions released from cells that were coinfected with M tagged with enhanced green fluorescent protein and M tagged with mCherry variants in which the late domains of one virus were inactivated by mutation showed a strong bias against the incorporation of the late-domain mutant into the released virions. In contrast, the intracellular expression and membrane association of the two variants were unaltered. These studies provide new tools for imaging particle assembly and enhance our resolution of existing models for assembly of VSV.IMPORTANCEAssembly of vesicular stomatitis virus (VSV) particles requires the separate trafficking of the viral replication machinery, a matrix protein (M) and a glycoprotein, to the plasma membrane. The matrix protein contains a motif termed a “late domain” that engages the host endosomal sorting complex required for transport (ESCRT) machinery to facilitate the release of viral particles. Inactivation of the late domains through mutation results in the accumulation of virions arrested at the point of release. In the study described here, we developed new tools to study VSV assembly by fusing fluorescent proteins to M and to a constituent of the replication machinery, the phosphoprotein (P). We used those tools to show that the late domains of M are required for efficient incorporation into viral particles and that the particles contain a variable quantity of M and P.

scholarly journals Influenza Virus Hemagglutinin and Neuraminidase, but Not the Matrix Protein, Are Required for Assembly and Budding of Plasmid-Derived Virus-Like Particles

2007 ◽  
Vol 81 (13) ◽  
pp. 7111-7123 ◽  
Author(s):  
Benjamin J. Chen ◽  
George P. Leser ◽  
Eiji Morita ◽  
Robert A. Lamb
Keyword(s):  
Influenza Virus ◽  
Culture Medium ◽  
Matrix Protein ◽  
Culture Media ◽  
Protein Composition ◽  
Multivesicular Body ◽  
Viral Proteins ◽  
Dominant Negative ◽  
The Matrix ◽  
Overexpression System

ABSTRACT For influenza virus, we developed an efficient, noncytotoxic, plasmid-based virus-like particle (VLP) system to reflect authentic virus particles. This system was characterized biochemically by analysis of VLP protein composition, morphologically by electron microscopy, and functionally with a VLP infectivity assay. The VLP system was used to address the identity of the minimal set of viral proteins required for budding. Combinations of viral proteins were expressed in cells, and the polypeptide composition of the particles released into the culture media was analyzed. Contrary to previous findings in which matrix (M1) protein was considered to be the driving force of budding because M1 was found to be released copiously into the culture medium when M1 was expressed by using the vaccinia virus T7 RNA polymerase-driven overexpression system, in our noncytotoxic VLP system M1 was not released efficiently into the culture medium. Additionally, hemagglutinin (HA), when treated with exogenous neuraminidase (NA) or coexpressed with viral NA, could be released from cells independently of M1. Incorporation of M1 into VLPs required HA expression, although when M1 was omitted from VLPs, particles with morphologies similar to those of wild-type VLPs or viruses were observed. Furthermore, when HA and NA cytoplasmic tail mutants were included in the VLPs, M1 failed to be efficiently incorporated into VLPs, consistent with a model in which the glycoproteins control virus budding by sorting to lipid raft microdomains and recruiting the internal viral core components. VLP formation also occurred independently of the function of Vps4 in the multivesicular body pathway, as dominant-negative Vps4 proteins failed to inhibit influenza VLP budding.

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