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Nicola T Wood

Publications and source records attributed to Nicola T Wood.

4 recordsLinked to original sources

Targeting of TMV movement protein to plasmodesmata requires the actin/ER network: evidence from FRAP.

Fluorescence recovery after photobleaching (FRAP) was used to study the mechanism by which fluorescent-protein-tagged movement protein (MP) of tobacco mosaic virus (TMV) is targeted to plasmodesmata (PD). The data show that fluorescence recovery in PD at the leading edge of an infection requires elements of the cortical actin/endoplasmic reticulum (ER) network and can occur in the absence of an intact microtubule (MT) cytoskeleton. Inhibitors of the actin cytoskeleton (latrunculin and cytochalasin) significantly inhibited MP targeting, while MT inhibitors (colchicine and oryzalin) did not. Application of sodium azide to infected cells implicated an active component of MP transfer to PD. Treatment of cells with Brefeldin A (BFA) at a concentration that caused reabsorption of the Golgi bodies into the ER (precluding secretion of viral MP) had no effect on MP targeting, while disruption of the cortical ER with higher concentrations of BFA caused significant inhibition. Our results support a model of TMV MP function in which targeting of MP to PD during infection is mediated by the actin/ER network.

Actins↗

14-3-3-affinity purification of over 200 human phosphoproteins reveals new links to regulation of cellular metabolism, proliferation and trafficking.

14-3-3-interacting proteins were isolated from extracts of proliferating HeLa cells using 14-3-3 affinity chromatography, eluting with a phosphopeptide that competes with targets for 14-3-3 binding. The isolated proteins did not bind to 14-3-3 proteins (14-3-3s) after dephosphorylation with protein phosphatase 2A (PP2A), indicating that binding to 14-3-3s requires their phosphorylation. The binding proteins identified by tryptic mass fingerprinting and Western blotting include many enzymes involved in generating precursors such as purines (AMP, GMP and ATP), FAD, NADPH, cysteine and S-adenosylmethionine, which are needed for cell growth, regulators of cell proliferation, including enzymes of DNA replication, proteins of anti-oxidative metabolism, regulators of actin dynamics and cellular trafficking, and proteins whose deregulation has been implicated in cancers, diabetes, Parkinsonism and other neurological diseases. Several proteins bound to 14-3-3-Sepharose in extracts of proliferating cells, but not in non-proliferating, serum-starved cells, including a novel microtubule-interacting protein ELP95 (EMAP-like protein of 95 kDa) and a small HVA22/Yop1p-related protein. In contrast, the interactions of 14-3-3s with the N-methyl-D-aspartate receptor 2A subunit and NuMA (nuclear mitotic apparatus protein) were not regulated by serum. Overall, our findings suggest that 14-3-3s may be central to integrating the regulation of biosynthetic metabolism, cell proliferation, survival, and other processes in human cells.

14-3-3 Proteins↗