The supersymmetric tensor hierarchy of N=1,d=4 supergravity

In this paper we construct the supersymmetric tensor hierarchy of N=1, d=4 supergravity. We find some differences with the general bosonic construction of 4-dimensional gauged supergravities. The global symmetry group of N=1,d=4 supergravity consists of three factors: the scalar manifold isometry group, the invariance group of the complex vector kinetic matrix and the U(1) R-symmetry group. In contrast to (half)-maximal supergravities, the latter two symmetries are not embedded into the isometry group of the scalar manifold. We identify some components of the embedding tensor with Fayet-Iliopoulos terms and we find that supersymmetry implies that the inclusion of R-symmetry as a factor of the global symmetry group requires a non-trivial extension of the standard p-form hierarchy. This extension involves additional 3- and 4-forms. One additional 3-form is dual to the superpotential (seen as a deformation of the simplest theory). We study the closure of the supersymmetry algebra on all the bosonic p-form fields of the hierarchy up to duality relations. In order to close the supersymmetry algebra without the use of duality relations one must construct the hierarchy in terms of supermultiplets. Such a construction requires fermionic duality relations among the hierarchy's fermions and these turn out to be local.Comment: Latex2e, 42 pages, no figures Improved version to be published in JEH

Kac-Moody Spectrum of (Half-)Maximal Supergravities

We establish the correspondence between, on one side, the possible gaugings and massive deformations of half-maximal supergravity coupled to vector multiplets and, on the other side, certain generators of the associated very extended Kac-Moody algebras. The difference between generators associated to gaugings and to massive deformations is pointed out. Furthermore, we argue that another set of generators are related to the so-called quadratic constraints of the embedding tensor. Special emphasis is placed on a truncation of the Kac-Moody algebra that is related to the bosonic gauge transformations of supergravity. We give a separate discussion of this truncation when non-zero deformations are present. The new insights are also illustrated in the context of maximal supergravity.Comment: Added references, published versio

Isolamento di cloni di cDNA per le subunit\ue0 VIa e VIIa della Citocromo c ossidasi umana (COX).

Descriviamo la caratterizzazione di cDNA per le isoforme epatica e muscolare della subunit\ue0 VIa e per l'isoformadella subunit\ue0 VIIa della citocromo c ossidasi umana (COX). I due cDNA della subunit\ue0 VIa costituiscono la prima coppia di geni per isoforma tessuto-specifica della COX ad essere identificata nell'uomo e rivestono un'importanza primaria per l'analisi dei difetti di COX che si manifestano con selettivo coinvolgimento muscolare

Transcription and translation of deleted mitochondrial genomes in Kearns-Sayre syndrome: implications for pathogenesis.

Large-scale deletions of human mitochondrial DNA (mtDNA) have been described in a clinical subgroup of mitochondrial encephalomyopathies associated with progressive external ophthalmoplegia and ragged-red fibers in skeletal muscle, including cases of Kearns-Sayre syndrome (KSS). Since the decrease in the activities of mtDNA-encoded respiratory-chain enzymes did not seem to be correlated to the sites of the deletions, the role played by the mtDNA deletions in the pathogenesis of these disorders has been unclear. To address this issue, we studied transcription and translation of deleted mtDNA in two patients with KSS harboring two different deletions. We found that the deleted genomes were transcriptionally active in both cases. Analysis of translation in one of the patients showed that the "fusion" mRNA derived from the region spanning the deletion did not seem to be translated. Thus, the biochemical defects in KSS can be explained by a lack of translation of mtDNA-encoded respiratory-chain polypeptides in some mitochondria, which, in turn, is probably due to the lack of indispensable mtDNA-encoded tRNAs in these organelles. These results imply that deleted mtDNAs may be segregated from normal genomes in this group of diseases. It seems likely that the absence of translation in proliferating mitochondria containing partially deleted genomes plays a major role in the pathogenesis of these disorders

Exploring the use of the bacterial conjugation system to deliver DNA to mitochondria.

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A new mutation associated with MELAS is located in a mitochondrial DNA polypeptide-coding gene

We report a patient with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) who harbored a novel missense mutation at mtDNA position 9957 in the gene specifying subunit III of cytochrome c oxidase (COX III). This T→C transition converted Phe-251, a highly conserved amino acid in the C-terminus of the polypeptide, to Leu. The mutation, which was not present in 107 normal controls or in 57 patients with various mitochondrial diseases, was heteroplasmic in both muscle and blood of the proband and in blood from his asymptomatic mother. These results provide evidence that the MELAS clinical phenotype can be due not only to mutations in mtDNA-encoded tRNA genes, but in polypeptide-coding genes as well

Sequence of a cDNA specifying subunit VIIa of human cytochrome c oxidase.

no abstract availabl

Tissue-specific expression and chromosome assignment of genes specifying two isoforms of subunit VIIa of human cytochrome c oxidase

Subunit VIIa of mammalian cytochrome c oxidase (COX; EC 1.9.3.1) exists in at least two isoforms, one present in all tissue types ('liver' isoform; COX VIIa-L) and the other specific for cardiac and skeletal muscle (COX VIIa-M). We have isolated a full-length cDNA encoding human COX VIIa-M. The deduced polypeptide represents the human ortholog of COX VIIa-M, as it shares 78% identity with bovine COX VIIa-M, but only 63% identity with human COX VIIa-L. Northern-blot analysis of primate tissues demonstrated that COXVIIa-M mRNA is present only in muscle tissues; in contrast, the COXVIIa-L mRNA is present in both muscle and nonmuscle tissues. Southern-blot hybridization of human-rodent cell hybrid genomic DNA indicates that the COXVHa-M gene maps to a single locus on chromosome 19, designated COX7AM. In contrast, COXVIIa-L cDNA probes hybridized to fragments from two COX7AL loci, on chromosomes 4 and 14. \ua9 1992

Multiple mtDNA deletions features in autosomal dominant and recessive diseases suggest distinct pathogeneses

Multiple mitochondrial DNA (mtDNA) deletions have been described in patients with autosomal dominant progressive external ophthalmoplegia (AD- PEO) and in autosomal recessive disorders including mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) and autosomal recessive cardiomyopathy ophthalmoplegia (ARCO). The pathogenic bases of these disorders are unknown. We studied three patients with AD-PEO and three patients with autosomal recessive (AR)-PEO (two patients with MNGIE and one patient with ARCO). Histochemistry and Southern blot analyses of DNA were performed in skeletal muscle from the patients. Muscle mtDNA was used to characterize the pattern and amounts of the multiple mtDNA rearrangements; PCR analysis was performed to obtain finer maps of the deleted regions in both conditions. The patients with AD-PEO had myopathic features; the patients with AR-PEO had multisystem disorders. The percentage of ragged-red and cytochrome c oxidase-negative fibers tended to be higher in muscle from the patients with AD-PEO (19% ± 13.9, 29.7 ± 26.3) than in muscle from the patients with AR-PEO (1.4% ± 1.4, 3.3% ± 3.2; p < 0.10). The sizes of the multiple mtDNA deletions ranged from approximately 4.0 to 10.0 kilobases in muscle from both groups of patients, and in both groups, we identified only deleted and no duplicated mtDNA molecules. Patients with AD-PEO harbored a greater proportion of deleted mtDNA species in muscle (31% ± 5.3) than did patients with AR-PEO (9.7% ± 9.1; p < 0.05). In the patients with AD-PEO, we identified a deletion that included the mtDNA heavy strand promoter (HSP) region, which had been previously described as the HSP deletion. The HSP deletion was not present in the patients with AR-PEO. Our findings show the clinical, histologic, and molecular genetic heterogeneity of these complex disorders. In particular, the proportions of multiple mtDNA deletions were higher in muscle samples from patients with AD-PEO than in those from patients with AR-PEO