scholarly journals Identification of the Yeast R-SNARE Nyv1p as a Novel Longin Domain-containing Protein

2006 ◽  
Vol 17 (10) ◽  
pp. 4282-4299 ◽  
Author(s):  
Wenyu Wen ◽  
Lu Chen ◽  
Hao Wu ◽  
Xin Sun ◽  
Mingjie Zhang ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Amino Acid ◽  
Magnetic Resonance ◽  
Adaptor Protein ◽  
Resonance Spectroscopy ◽  
Amino Acid Substitutions ◽  
Sorting Signals ◽  
Distinct Role

Using nuclear magnetic resonance spectroscopy, we establish that the N-terminal domain of the yeast vacuolar R-SNARE Nyv1p adopts a longin-like fold similar to those of Sec22b and Ykt6p. Nyv1p is sorted to the limiting membrane of the vacuole via the adaptor protein (AP)3 adaptin pathway, and we show that its longin domain is sufficient to direct transport to this location. In contrast, we found that the longin domains of Sec22p and Ykt6p were not sufficient to direct their localization. A YXXΦ-like adaptin-dependent sorting signal (Y31GTI34) unique to the longin domain of Nyv1p mediates interactions with the AP3 complex in vivo and in vitro. We show that amino acid substitutions to Y31GTI34 (Y31Q;I34Q) resulted in mislocalization of Nyv1p as well as reduced binding of the mutant protein to the AP3 complex. Although the sorting of Nyv1p to the limiting membrane of the vacuole is dependent upon the Y31GTI34 motif, and Y31 in particular, our findings with structure-based amino acid substitutions in the mu chain (Apm3p) of yeast AP3 suggest a mechanistically distinct role for this subunit in the recognition of YXXΦ-like sorting signals.

Nuclear Magnetic Resonance Spectroscopy Studies of Cancer Cell Metabolism

1997 ◽  
Author(s):  
O. Kaplan ◽  
J.S. Cohen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Cellular Metabolism ◽  
Resonance Spectroscopy ◽  
Nmr Studies ◽  
Nuclear Magnetic

Nuclear magnetic resonance spectroscopy (NMR) is a powerful technique that provides information on biochemical status and physiological processes both in-vitro and in-vivo. The metabolism of intact cells and tissues can be studied in a continuous manner, and thus, NMR is a unique non-invasive research tool enabling detection of the metabolic changes as they occur (Cohen et al., 1983; Morris, 1988; Daly and Cohen, 1989). The first NMR study of cellular metabolism was done some 20 years ago, when Moon and Richards reported on the diphosphoglyceric acid (DPG) and pH shifts in erythrocytes (Moon, and Richards, 1973). NMR studies of metabolism of tumor cells were initiated by Navon et al. who investigated phosphorylated compounds in Ehrlich ascites cells (Navon etal., 1977). The choice of the element and isotope for a specific study of metabolism depends on its NMR properties, and the required data. The proton has the highest NMR sensitivity, and is the most abundant nucleus in biological molecules. However, this may cause difficulties in the interpretation and assignment of the 1H NMR spectrum. Moreover, since metabolic studies are usually performed in aqueous solutions, the huge signal from the water protons should be suppressed. Similarly, the wide signals arising from proteins and membrane components should be suppressed. These problems can be addressed now by several innovative NMR methods (Daniels et al., 1976; van Zijl and Cohen, 1992). The most widely used nucleus in NMR studies of metabolism has been 31p (see reviews Cohen (1988); Kaplan et al. (1992)). Phosphorous NMR spectroscopy can provide data on energy metabolism and substrate utilization, phospholipid pathways, precise intracellular pH, and membrane permeability and ion and water distribution. The spectrum is easy to interpret, but the number of compounds which are detectable is limited. Carbon NMR is also useful for NMR studies of metabolism since it is found in most biological compounds; however, 13C has a natural abundance of only 1.1%, and 13C enrichment is necessary. Other nuclei which are used less often in NMR studies of cellular metabolism are 23Na (Gupta et al., 1984), 19F (Malet-Martino, et al., 1986), and rarely 15N (Legerton et al., 1983) and 39K (Brophy et al., 1983).

scholarly journals Altered Metabolic Profile in Congenital Lung Lesions Revealed by 1H Nuclear Magnetic Resonance Spectroscopy

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Maria Chiara Mimmi ◽  
Maurizio Ballico ◽  
Ghassan Nakib ◽  
Valeria Calcaterra ◽  
Jose Louis Peiro ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Large Scale ◽  
Relative Concentration ◽  
Control Sample ◽  
Resonance Spectroscopy ◽  
Lung Lesions ◽  
Nuclear Magnetic

Congenital lung lesions are highly complex with respect to pathogenesis and treatment. Large-scale analytical methods, like metabolomics, are now available to identify biomarkers of pathological phenotypes and to facilitate clinical management. Nuclear magnetic resonance (NMR) is a unique tool for translational research, as in vitro results can be potentially translated into in vivo magnetic resonance protocols. Three surgical biopsies, from congenital lung malformations, were analyzed in comparison with one control sample. Extracted hydrophilic metabolites were submitted to high resolution 1H NMR spectroscopy and the relative concentration of 12 metabolites was estimated. In addition, two-dimensional NMR measurements were performed to complement the results obtained from standard monodimensional experiments. This is one of the first reports of in vitro metabolic profiling of congenital lung malformation. Preliminary data on a small set of samples highlights some altered metabolic ratios, dealing with the glucose conversion to lactate, to the relative concentration of phosphatidylcholine precursors, and to the presence of myoinositol. Interestingly some relations between congenital lung lesions and cancer metabolic alterations are found.

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