Age-associated cellular relocation of Sod 1 as a self-defense is a futile mechanism to prevent vascular aging

Vascular aging is characterized by the presence of chronic oxidative stress. Although cytosolic Sod 1 has a key role in the detoxification of superoxide ((*)O(2)(-)), little is known about its importance in vascular aging. We found that inhibition of Sod 1 had no effect on (*)O2- generation. Furthermore, its expression decreased in an age-dependent manner. Interestingly, Sod 1 loses its membrane-association and is also lost from the caveolae with increasing age. Instead, a relocation of Sod 1 to the mitochondria takes place, presumably in an attempt to maintain mitochondrial integrity and to counter-balance age-associated oxidative stress. Unlike Sod 2, which is constitutively expressed in mitochondria to control (*)O2- radical fluxes, Sod 1 is not inactivated by peroxynitrite and is not nitrated as a function of age. These novel insights into oxidative stress-associated vascular aging and the understanding about how redox-systems are regulated in old age may identify new targets to ameliorate aging as the greatest cardiovascular risk factor.     

Glycoprofiling of the Human Salivary Proteome

Introduction  Glycosylation is an important component for a number of biological processes and is perhaps the most abundant and complicated of the known post-translational modifications found on proteins. Methods  This work combines two-dimensional (2-D) polyacrylamide gel electrophoresis and lectin blotting to map the salivary glycome and mass spectrometry to identity the proteins that are associated with the glycome map. A panel of 15 lectins that recognize six sugar-specific categories was used to visualize the type and extent of glycosylation in saliva from two healthy male individuals. Lectin blots were compared to 2-D gels stained either with Sypro Ruby (protein stain) or Pro-Q Emerald 488 (glycoprotein stain). Results  Each lectin shows a distinct pattern, even those belonging to the same sugar-specific category. In addition, the glycosylation profiles generated from the lectin blots show that most salivary proteins are glycosylated and that the profiles are more widespread than is demonstrated by the glycoprotein-stained gel. Finally, the coreactivity between lectins was measured to determine what types of glycan structures are associated with one another and also the population variation of the lectin reactivity for 66 individuals were reported. Conclusions  This starting 2-D gel glycosylation reference map shows that the scientifically accepted, individual oligosaccharide variability is not limited to a few large glycoproteins such as MUC5B, but are found on most members of the salivary proteome. Finally, in order to see the full range of oligosaccharide distribution, multiple reagents or lectins are needed. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The allotypic patchwork pattern of the rabbit IGKC1 allele b5wf: genic exchange or common ancestry?

 The protein sequences of different alleles of the rabbit immunoglobulin IGKC1 gene can differ at more than 40% of the amino acid positions. This exceptional degree of allelic divergence raises questions concerning the causal underlying mechanisms. We report the DNA sequence of the coding region of an allotype which is associated with the mitochondrial lineage A (Southwestern Spain). At the serological level, this b5wf allotype presents a patchwork of antigenic determinants which in domestic breeds are characteristic of the b4, b5, and b6 allotypes. The inferred protein sequence of the b5wf allotype was found to differ from that of the b4, b5, and b6 allotypes at 25, 10, and 15% of the amino acid positions, respectively. Sequence comparisons show that the b4-specific epitopes of the b5wf allotype are probably due to a shared ThrThrGlnThr motif at Kabat positions 153–156. Similarly, the shared b5-specific determinants should relate to the motifs 161ThrSerLys163 and/or 182LysSerAspGlu185. A monoclonal antibody binding epitope shared among the b5wf, b5, and b6 sequences appeared to be correlated with the presence of Asp190. Although there is evidence of interallelic genic exchange, sequence comparisons suggest that the apparent mosaic structure of the b5wf allotype is better explained by common ancestry and point mutation. Received: 22 June 1998 / Revised: 18 August 1998     

Biological active peptides in human urine: III. Inhibitors of the growth of human leukemia, osteosarcoma, and HeLa cells.

Medium-sized peptides isolated from normal humans urine were tested for their effect on DNA, RNA, and protein synthesis, and mitosis, in tissue culture of human myeloblastic leukemia, osteosarcoma, and HeLa cells. Two types of antineoplastic peptides were found. One type consists of strongly acidic peptides (probably sulfated glycopeptides) which act specifically on different kinds of neoplasma. The other type comprises slightly acidic and neutral peptides, and has broad specificity. The active peptides produce up to 97% inhibition of DNA synthesis and mitosis in the neoplastic cells in tissue culture. The peptide fraction which has broad specificity was tested in different concentrations and gave good dose-response relationship.     

Roles of Abf1, Npl3, and Ycl54 in Silencing in Saccharomyces Cerevisiae

A sensitized genetic screen was carried out to identify essential genes involved in silencing in Saccharomyces cerevisiae. This screen identified temperature-sensitive alleles of ORC2 and ORC5, as described elsewhere, and ABF1, NPL3, and YCL54, as described here. Alleles of ABF1 that caused silencing defects provided the genetic proof of Abf1p's role in silencing. The roles of Npl3p and Ycl54p are less clear. These proteins did not act exclusively through any one of the three protein binding sites of the HMR-E silencer. Unlike the orc2, orc5, and abf1 mutations that were isolated in the same (or a similar) screen for silencing mutants, neither temperature-sensitive mutation in NPL3 or YCL54 caused overt replication defects.     

The Trichomonas vaginalis hydrogenosome proteome is highly reduced relative to mitochondria, yet complex compared with mitosomes

The human pathogen Trichomonas vaginalis lacks conventional mitochondria and instead contains divergent mitochondrial-related organelles. These double-membrane bound organelles, called hydrogenosomes, produce molecular hydrogen. Phylogenetic and biochemical analyses of hydrogenosomes indicate a common origin with mitochondria; however identification of hydrogenosomal proteins and studies on its metabolism have been limited. Here we provide a detailed proteomic analysis of the T. vaginalis hydrogenosome. The proteome of purified hydrogenosomes consists of 569 proteins, a number substantially lower than the 1,000-1,500 proteins reported for fungal and animal mitochondrial proteomes, yet considerably higher than proteins assigned to mitosomes. Pathways common to and distinct from both mitochondria and mitosomes were revealed by the hydrogenosome proteome. Proteins known to function in amino acid and energy metabolism, Fe-S cluster assembly, flavin-mediated catalysis, oxygen stress response, membrane translocation, chaperonin functions, proteolytic processing and ATP hydrolysis account for ～30% of the hydrogenosome proteome. Of the 569 proteins in the hydrogenosome proteome, many appear to be associated with the external surface of hydrogenosomes, including large numbers of GTPases and ribosomal proteins. Glycolytic proteins were also found to be associated with the hydrogenosome proteome, similar to that previously observed for mitochondrial proteomes. Approximately 18% of the hydrogenosomal proteome is composed of hypothetical proteins of unknown function, predictive of multiple activities and properties yet to be uncovered for these highly adapted organelles.