Premium
NIP45 Promotes Telomere Targeting to PML Bodies in ALT Cells
Author(s) -
Farley Demetra D,
Yu Hongtao
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.933.6
Subject(s) - sumo protein , telomere , telomerase , microbiology and biotechnology , telomere binding protein , homologous recombination , biology , cancer cell , dna binding protein , dna , genetics , cancer , ubiquitin , gene , transcription factor
Telomere length maintenance is critical for continued cell proliferation. Certain cancer cells do not have active telomerase and use homologous recombination to lengthen their telomeres, a mechanism referred to as alternative lengthening of telomeres (ALT). We have previously shown that the SMC5/6 complex is required for telomere length maintenance in ALT cells. The SMC5/6 component MMS21 sumoylates multiple telomere‐binding proteins and promotes telomere targeting to ALT‐associated PML bodies (APBs). In this study, we show that the SUMO‐like protein NIP45 is also required for targeting telomeres to APBs. NIP45 itself localizes to PML bodies and promotes MMS21‐dependent sumoylation of telomere‐binding proteins. The C‐terminal SUMO‐like domain of NIP45 is sufficient to restore both APB formation and sumoylation of telomere‐binding proteins in NIP45 RNAi cells. Our results suggest that NIP45 enables PML‐body recruitment and sumoylation of telomere‐binding proteins, thus promoting APB formation in ALT cells. This work was supported by a National Research Service Award grant 5 T32 GM 8203‐24 to Demetra D. Farley.