VAMP726 and VAMP725 regulate vesicle secretion and pollen tube growth in Arabidopsis.

VAMP726/VAMP725 and SYP131 can form a part of a SNARE complex to mediate vesicle secretion at the pollen tube apex. Secretory vesicle fusion with the plasma membrane of the pollen tube tip is a key step in pollen tube growth. Membrane fusion was mediated by SNAREs.

The immunostimulatory effects and pro-apoptotic activity of rhCNB against Lewis lung cancer is mediated by Toll-like receptor 4.

Background: Recombinant human calcineurin B subunit (rhCNB) has been shown to be an immune-stimulatory protein promoting cytokine production and inducing phenotypic maturation of Dendritic cells (DCs). In vivo, it has good antitumor efficacy, and has potential as an antitumor drug. Exogenous rhCNB was found to be internalized into tumor cells via the Toll-like receptor 4 (TLR4) complex, but it was not known whether its immuno-modulatory and antitumor functions involved entry by this same route.

Identification of a targeting-delivery peptide based on rhCNB.

Calcineurin B subunit (CNB) is the regulatory subunit of calcineurin (CN), and its classical function is to regulate the activity of CN. Research in our laboratory has revealed that the recombinant human CNB (rhCNB) is a good antitumor candidate and can be internalized by tumor cells via TLR4 receptor complexes and targeted to tumor tissue in nude mice. However, the fragment or domain of rhCNB mediating internalization and target delivery has not been identified.

Studies on the activation of isocitrate dehydrogenase kinase/phosphatase (AceK) by Mn and Mg.

Isocitrate dehydrogenase kinase/phosphatase (AceK) is a bifunctional enzyme with both kinase and phosphatase activities that are activated by Mg. We have studied the interactions of Mnand Mg with AceK using isothermal titration calorimetry (ITC) combined with molecular docking simulations and show for the first time that Mn also activates the enzyme activities. However, Mn and Mg exert their effects by different mechanisms.

Loopβ3αC plays an important role in the structure and function of isocitrate dehydrogenase kinase/phosphatase.

This work aims to investigate the role of the loopβ3αC amino acids in the structure and function of isocitrate dehydrogenase kinase/phosphatase (AceK). The results demonstrate that the precise configuration of loopβ3αC is very important for AceK structure and function: structural changes alter the affinity of the enzyme for the isocitrate dehydrogenase (ICDH), which modifies enzyme activity. Intriguingly, D340 is significant for the retention of kinase and phosphatase activities, for the conformational stability of AceK and for binding ICDH.

The new immunosuppressant, isogarcinol, binds directly to its target enzyme calcineurin, unlike cyclosporin A and tacrolimus.

Isogarcinol, a bioactive polyisoprenylated benzophenone derivative isolated from Garcinia mangostana L., has been shown previously to exert a strong inhibitory effect on calcineurin and is thus a potential oral, low-toxicity immunomodulatory drug. In the present study, enzyme kinetic analysis showed that inhibition of calcineurin by isogarcinol was competitive.