An archaeal homolog of proteasome assembly factor functions as a proteasome activator.

Autor: Kentaro Kumoi, Tadashi Satoh, Kazuyoshi Murata, Takeshi Hiromoto, Tsunehiro Mizushima, Yukiko Kamiya, Masanori Noda, Susumu Uchiyama, Hirokazu Yagi, Koichi Kato
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: PLoS ONE, Vol 8, Iss 3, p e60294 (2013)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0060294
Popis: Assembly of the eukaryotic 20S proteasome is an ordered process involving several proteins operating as proteasome assembly factors including PAC1-PAC2 but archaeal 20S proteasome subunits can spontaneously assemble into an active cylindrical architecture. Recent bioinformatic analysis identified archaeal PAC1-PAC2 homologs PbaA and PbaB. However, it remains unclear whether such assembly factor-like proteins play an indispensable role in orchestration of proteasome subunits in archaea. We revealed that PbaB forms a homotetramer and exerts a dual function as an ATP-independent proteasome activator and a molecular chaperone through its tentacle-like C-terminal segments. Our findings provide insights into molecular evolution relationships between proteasome activators and assembly factors.
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