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Chm7 and Heh1 collaborate to link nuclear pore complex quality control with nuclear envelope sealing
Author(s) -
Webster Brant M,
Thaller David J,
Jäger Jens,
Ochmann Sarah E,
Borah Sapan,
Lusk C Patrick
Publication year - 2016
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.15252/embj.201694574
Subject(s) - biology , nuclear pore , link (geometry) , envelope (radar) , quality (philosophy) , microbiology and biotechnology , physics , computer science , nucleus , telecommunications , computer network , radar , quantum mechanics
Abstract The integrity of the nuclear envelope barrier relies on membrane remodeling by the ESCRT s, which seal nuclear envelope holes and contribute to the quality control of nuclear pore complexes ( NPC s); whether these processes are mechanistically related remains poorly defined. Here, we show that the ESCRT ‐ II / III chimera, Chm7, is recruited to a nuclear envelope subdomain that expands upon inhibition of NPC assembly and is required for the formation of the storage of improperly assembled NPC s ( SINC ) compartment. Recruitment to sites of NPC assembly is mediated by its ESCRT ‐ II domain and the LAP 2‐emerin‐ MAN 1 ( LEM ) family of integral inner nuclear membrane proteins, Heh1 and Heh2. We establish direct binding between Heh2 and the “open” forms of both Chm7 and the ESCRT ‐ III , Snf7, and between Chm7 and Snf7. Interestingly, Chm7 is required for the viability of yeast strains where double membrane seals have been observed over defective NPC s; deletion of CHM 7 in these strains leads to a loss of nuclear compartmentalization suggesting that the sealing of defective NPC s and nuclear envelope ruptures could proceed through similar mechanisms.