Regulatory proteins of the proteasome.
The function of the proteasome is controlled by a variety of specific regulatory proteins including activators, inhibitors, and modulators. Two recently discovered activators, termed PA28 and PA700, bind to the terminal rings of the proteasome to form proteasome-regulatory complexes which display greatly increased proteolytic activity. PA28 is a high-affinity activator of the proteasome's multiple peptidase activities. The carboxyl terminus of PA28 is required for its binding to the proteasome. PA700 binds to the proteasome via an ATP-dependent mechanism. PA700 has ATPase activity, and at least four of PA700's 16 subunits are members of a protein family containing a concensus sequence for ATP binding. Proteasome-PA700 complexes are activated with respect to both the hydrolysis of peptide substrates and the hydrolysis of ubiquitinated proteins.
DeMartino
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GN
Department of Physiology, University of Texas Southwestern Medical Center, Dallas 75235.
Slaughter
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CA
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000737:chemistry / Q000378:metabolism; D004789:Enzyme Activation; D006801:Humans; D015394:Molecular Structure; D009097:Multienzyme Complexes / Q000737:chemistry / Q000378:metabolism*; D009124:Muscle Proteins; D010447:Peptide Hydrolases / Q000737:chemistry / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*
D015853:Cysteine Proteinase Inhibitors; D009097:Multienzyme Complexes; D009124:Muscle Proteins; C085834:PA700 proteasome activator; C085047:PSME1 protein, human; D011506:Proteins; D000255:Adenosine Triphosphate; D010447:Peptide Hydrolases; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease