Distributions of switching times of single-domain particles using a time quantified Monte Carlo method

Using a time quantified Monte Carlo scheme we performed simulations of the switching time distribution of single mono-domain particles in the Stoner-Wohlfarth approximation. We considered uniaxial anisotropy and different conditions for the external applied field. The results obtained show the switching time distribution can be well described by two relaxation times, either when the applied field is parallel to the easy axis or for an oblique external field and a larger damping constant. We found that in the low barrier limit these relaxation times are in very good agreement with analytical results obtained from solutions of the Fokker-Planck equation related to this problem. When the damping is small and the applied field is oblique the shape of the distribution curves shows several peaks and resonance effects.Comment: 12 pages, 5 figures. New references, changes in the title and minor correction

Control of protein palmitoylation by regulating substrate recruitment to a zDHHC-protein acyltransferase

Although palmitoylation regulates numerous cellular processes, as yet efforts to manipulate this post-translational modification for therapeutic gain have proved unsuccessful. The Na-pump accessory sub-unit phospholemman (PLM) is palmitoylated by zDHHC5. Here, we show that PLM palmitoylation is facilitated by recruitment of the Na-pump α sub-unit to a specific site on zDHHC5 that contains a juxtamembrane amphipathic helix. Site-specific palmitoylation and GlcNAcylation of this helix increased binding between the Na-pump and zDHHC5, promoting PLM palmitoylation. In contrast, disruption of the zDHHC5-Na-pump interaction with a cell penetrating peptide reduced PLM palmitoylation. Our results suggest that by manipulating the recruitment of specific substrates to particular zDHHC-palmitoyl acyl transferases, the palmitoylation status of individual proteins can be selectively altered, thus opening the door to the development of molecular modulators of protein palmitoylation for the treatment of disease

Cysteine post-translational modifications regulate protein interactions of caveolin-3

Caveolae are small flask-shaped invaginations of the surface membrane which are proposed to recruit and co-localize signaling molecules. The distinctive caveolar shape is achieved by the oligomeric structural protein caveolin, of which three isoforms exist. Aside from the finding that caveolin-3 is specifically expressed in muscle, functional differences between the caveolin isoforms have not been rigorously investigated. Caveolin-3 is relatively cysteine-rich compared to caveolins 1 and 2, so we investigated its cysteine post-translational modifications. We find that caveolin-3 is palmitoylated at 6 cysteines and becomes glutathiolated following redox stress. We map the caveolin-3 palmitoylation sites to a cluster of cysteines in its C terminal membrane domain, and the glutathiolation site to an N terminal cysteine close to the region of caveolin-3 proposed to engage in protein interactions. Glutathiolation abolishes caveolin-3 interaction with heterotrimeric G protein alpha subunits. Our results indicate that a caveolin-3 oligomer contains up to 66 palmitates, compared to up to 33 for caveolin-1. The additional palmitoylation sites in caveolin-3 therefore provide a mechanistic basis by which caveolae in smooth and striated muscle can possess unique phospholipid and protein cargoes. These unique adaptations of the muscle-specific caveolin isoform have important implications for caveolar assembly and signaling.</p

Cysteine post-translational modifications regulate protein interactions of caveolin-3

Caveolae are small flask-shaped invaginations of the surface membrane which are proposed to recruit and co-localize signaling molecules. The distinctive caveolar shape is achieved by the oligomeric structural protein caveolin, of which three isoforms exist. Aside from the finding that caveolin-3 is specifically expressed in muscle, functional differences between the caveolin isoforms have not been rigorously investigated. Caveolin-3 is relatively cysteine-rich compared to caveolins 1 and 2, so we investigated its cysteine post-translational modifications. We find that caveolin-3 is palmitoylated at 6 cysteines and becomes glutathiolated following redox stress. We map the caveolin-3 palmitoylation sites to a cluster of cysteines in its C terminal membrane domain, and the glutathiolation site to an N terminal cysteine close to the region of caveolin-3 proposed to engage in protein interactions. Glutathiolation abolishes caveolin-3 interaction with heterotrimeric G protein alpha subunits. Our results indicate that a caveolin-3 oligomer contains up to 66 palmitates, compared to up to 33 for caveolin-1. The additional palmitoylation sites in caveolin-3 therefore provide a mechanistic basis by which caveolae in smooth and striated muscle can possess unique phospholipid and protein cargoes. These unique adaptations of the muscle-specific caveolin isoform have important implications for caveolar assembly and signaling.</p

FAPRI 2004 U.S. and World Agricultural Outlook

Crop Production/Industries, Livestock Production/Industries,

FAPRI 2006 U.S. and World Agricultural Outlook

The FAPRI 2006 U.S. and World Agricultural Outlook presents projections of world agricultural production, consumption, and trade under average weather patterns, existing farm policy, and policy commitments under current trade agreements and custom unions. Despite continued high energy prices, world economic growth is expected to remain strong in the coming decade, above 3% per annum. Other major drivers of the 2006 baseline include new bio-energy policies in several large countries, EU sugar policy reform, sanitary and phytosanitary (SPS) shocks in livestock and poultry markets, and movements in the exchange rate.Crop Production/Industries, International Relations/Trade, Livestock Production/Industries,

FAPRI 2005 U.S. and World Agricultural Outlook

Crop Production/Industries, Livestock Production/Industries,

Cysteine post-translational modifications regulate protein interactions of caveolin-3

Caveolae are small flask-shaped invaginations of the surface membrane which are proposed to recruit and co-localize signaling molecules. The distinctive caveolar shape is achieved by the oligomeric structural protein caveolin, of which three isoforms exist. Aside from the finding that caveolin-3 is specifically expressed in muscle, functional differences between the caveolin isoforms have not been rigorously investigated. Caveolin-3 is relatively cysteine-rich compared to caveolins 1 and 2, so we investigated its cysteine post-translational modifications. We find that caveolin-3 is palmitoylated at 6 cysteines and becomes glutathiolated following redox stress. We map the caveolin-3 palmitoylation sites to a cluster of cysteines in its C terminal membrane domain, and the glutathiolation site to an N terminal cysteine close to the region of caveolin-3 proposed to engage in protein interactions. Glutathiolation abolishes caveolin-3 interaction with heterotrimeric G protein alpha subunits. Our results indicate that a caveolin-3 oligomer contains up to 66 palmitates, compared to up to 33 for caveolin-1. The additional palmitoylation sites in caveolin-3 therefore provide a mechanistic basis by which caveolae in smooth and striated muscle can possess unique phospholipid and protein cargoes. These unique adaptations of the muscle-specific caveolin isoform have important implications for caveolar assembly and signaling

FAPRI 2006 U.S. and World Agricultural Outlook

The FAPRI 2006 U.S. and World Agricultural Outlook presents projections of world agricultural production, consumption, and trade under average weather patterns, existing farm policy, and policy commitments under current trade agreements and custom unions. Despite continued high energy prices, world economic growth is expected to remain strong in the coming decade, above 3% per annum. Other major drivers of the 2006 baseline include new bio-energy policies in several large countries, EU sugar policy reform, sanitary and phytosanitary (SPS) shocks in livestock and poultry markets, and movements in the exchange rate

FAPRI 2004 U.S. and World Agricultural Outlook

The FAPRI 2004 U.S. and World Agricultural Outlook presents final projections of world agricultural production, consumption, and trade. Food and Agricultural Policy Research Institute (FAPRI) projections assume average weather patterns worldwide, existing policy, policy commitments under current trade agreements, and new policy changes such as the enlargement of the European Union and Common Agricultural Policy reforms. FAPRI projections do not include conjectures on potential policy changes. The major macroeconomic drivers of the 2004 FAPRI baseline are the continuing solid economic growth worldwide, and currency movements against the U.S. dollar