7 research outputs found
PIP30/FAM192A is a novel regulator of the nuclear proteasome activator PA28γ
PA28γ is a nuclear activator of the 20S proteasome involved in the regulation of several essential cellular processes, such as cell proliferation, apoptosis, nuclear dynamics, and cellular stress response. Unlike the 19S regulator of the proteasome, which specifically recognizes ubiquitylated proteins, PA28γ promotes the degradation of several substrates by the proteasome in an ATP- and ubiquitin-independent manner. However, its exact mechanisms of action are unclear and likely involve additional partners that remain to be identified. Here we report the identification of a cofactor of PA28γ, PIP30/FAM192A. PIP30 binds directly and specifically via its C-terminal end and in an interaction stabilized by casein kinase 2 phosphorylation to both free and 20S proteasome-associated PA28γ. Its recruitment to proteasome-containing complexes depends on PA28γ and its expression increases the association of PA28γ with the 20S proteasome in cells. Further dissection of its possible roles shows that PIP30 alters PA28γ-dependent activation of peptide degradation by the 20S proteasome in vitro and negatively controls in cells the presence of PA28γ in Cajal bodies by inhibition of its association with the key Cajal body component coilin. Taken together, our data show that PIP30 deeply affects PA28γ interactions with cellular proteins, including the 20S proteasome, demonstrating that it is an important regulator of PA28γ in cells and thus a new player in the control of the multiple functions of the proteasome within the nucleus
Correction to “Label-Free Quantitative Proteomics Reveals the Dynamics of Proteasome Complexes Composition and Stoichiometry in a Wide Range of Human Cell Lines”
Correction to “Label-Free
Quantitative Proteomics
Reveals the Dynamics of Proteasome Complexes Composition and Stoichiometry
in a Wide Range of Human Cell Lines
Label-Free Quantitative Proteomics Reveals the Dynamics of Proteasome Complexes Composition and Stoichiometry in a Wide Range of Human Cell Lines
The
proteasome is the main proteolytic system involved in intracellular
proteins homeostasis in eukaryotes. Although the structure of proteasome
complexes has been well characterized, the distribution of its activators
and associated proteins are less studied. Here, we determine the composition
and the stoichiometry of proteasome complexes and their associated
proteins in a wide range of human cell lines using a one-step affinity
purification method and a label-free quantitative proteomic approach.
We show that proteasome complexes are highly dynamic protein assemblies,
the activity of which being regulated at different levels by variations
in the stoichiometry of bound regulators, in the composition of catalytic
subunits and associated proteins, and in the rate of the 20S catalytic
core complex assembly
Label-Free Quantitative Proteomics Reveals the Dynamics of Proteasome Complexes Composition and Stoichiometry in a Wide Range of Human Cell Lines
The
proteasome is the main proteolytic system involved in intracellular
proteins homeostasis in eukaryotes. Although the structure of proteasome
complexes has been well characterized, the distribution of its activators
and associated proteins are less studied. Here, we determine the composition
and the stoichiometry of proteasome complexes and their associated
proteins in a wide range of human cell lines using a one-step affinity
purification method and a label-free quantitative proteomic approach.
We show that proteasome complexes are highly dynamic protein assemblies,
the activity of which being regulated at different levels by variations
in the stoichiometry of bound regulators, in the composition of catalytic
subunits and associated proteins, and in the rate of the 20S catalytic
core complex assembly
Adipocyte Exosomes Promote Melanoma Aggressiveness through Fatty Acid Oxidation: A Novel Mechanism Linking Obesity and Cancer
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