PPP1R2 stimulates protein phosphatase-1 through stabilisation of dynamic subunit interactions.

Protein Ser/Thr phosphatase PP1 is always associated with one or two regulatory subunits or RIPPOs. One of the earliest evolved RIPPOs is PPP1R2, also known as Inhibitor-2. Since its discovery nearly 5 decades ago, PPP1R2 has been variously described as an inhibitor, activator or (metal) chaperone of PP1, but it is still unknown how PPP1R2 affects the function of PP1 in intact cells.

(Ashwagandha) Improves Spatial Memory, Anxiety and Depressive-like Behavior in the 5xFAD Mouse Model of Alzheimer's Disease.

(WS), also known as ashwagandha, is a popular botanical supplement used to treat various conditions including memory loss, anxiety and depression. Previous studies from our group showed an aqueous extract of WS root (WSAq) enhances cognition and alleviates markers for depression in . Here, we sought to confirm these effects in the 5xFAD mouse model of β-amyloid (Aβ) accumulation.

Protocol for analyzing protein-protein interactions by split-luciferase complementation assays in human cell lysates.

Here, we present a lysate-based split-luciferase assay for examining protein-protein interactions (PPIs) in HEK293T cell lysates, exemplified by interactions between subunits of protein phosphatase PP1. We describe steps for storing and re-using lysates, sensor design, assay setup/optimization, and high-throughput screening of compound libraries. We then detail procedures for applying the assay as a research tool to characterize the dynamics of PPIs, which we illustrate with specific examples.

Spontaneous and chaperone-assisted metal loading in the active site of protein phosphatase-1.

Protein phosphatase PP1 has two active-site metals (Zn/Fe) that are essential for catalysis. However, when expressed in bacteria, PP1 has two Mn-ions in its active site, indicating that the incorporation of Zn/Fe depends on additional eukaryotic component(s). Here, we used purified, metal-deficient PP1 to study metal incorporation.

SDS22 coordinates the assembly of holoenzymes from nascent protein phosphatase-1.

SDS22 forms an inactive complex with nascent protein phosphatase PP1 and Inhibitor-3. SDS22:PP1:Inhibitor-3 is a substrate for the ATPase p97/VCP, which liberates PP1 for binding to canonical regulatory subunits. The exact role of SDS22 in PP1-holoenzyme assembly remains elusive.