Taking a bite: proteasomal protein processing.
The proteasome is a hollow cylindrical protease that contains active sites concealed within its central cavity. Proteasomes usually completely degrade substrates into small peptides, but in a few cases, degradation can yield biologically active protein fragments. Examples of this are the transcription factors NF-kappa B, Spt23p and Mga2p, which are generated from precursors by proteasomal processing. How distinct protein domains are spared from degradation remains a matter of debate. Here, we discuss several models and suggest a novel mechanism for proteasomal processing.
Rape
Michael
M
Department of Molecular Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18a, 82152 Martinsried, Germany.
Jentsch
Stefan
S
D000818:Animals; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D008954:Models, Biological; D009097:Multienzyme Complexes / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism
D009097:Multienzyme Complexes; D016328:NF-kappa B; D014157:Transcription Factors; D025801:Ubiquitin; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex