English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

At least two signalling systems have the potential to contribute to the activation of protein kinase C (PKC) family members such as PKCepsilon. One of these is phosphoinositide 3-kinase (PI 3-kinase), whose lipid products activate PKCepsilon in vitro and in living cells. The recent observation that there are multiple waves of PI 3-kinase and PKCepsilon activity within the G(0)-to-S phase interval provides a new opportunity to investigate the relationship between these two signalling enzymes in vivo. We have assessed the relative importance of the early and late waves of PI 3-kinase activity for the corresponding waves of PKCepsilon activity. Blocking the first phase of PI 3-kinase activity inhibited both early and late activation of PKCepsilon. In contrast, the second wave of PI 3-kinase activity was dispensable for late activation of PKCepsilon. These findings suggested that early PI 3-kinase activation induced a stable change in PKCepsilon, which predisposed it to subsequent activation by lipid cofactors. Indeed, partial proteolysis of PKCepsilon indicated that early activation of PI 3-kinase led to a conformation change in PKCepsilon that persisted as the activity of PKCepsilon cycled. We propose a two-step hypothesis for the activation of PKCepsilon in vivo. One step is stable and depends on PI 3-kinase, whereas the other is transient and may depend on the availability of lipid cofactors. Finally, these studies reveal that PI 3-kinase and PKCepsilon are capable of communicating over a relatively long time interval and begin to elucidate the mechanism.

biochemical journal

Early phosphoinositide 3-kinase activity is required for late activation of protein kinase Cε in platelet-derived-growth-factor-stimulated cells: evidence for signalling across a large temporal gap