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O‐GlcNAc Transferase (OGT) Regulates Nucleolar Organization
Author(s) -
Zeidan Quira,
Hart Gerald Warren
Publication year - 2011
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.25.1_supplement.513.5
Ribosomal proteins assemble around rRNA in the nucleolus. Nucleolar organization is partly maintained by the dynamics of fibrillarin. We have shown that the 60S peak increases in the cytoplasm of cells overexpressing OGT. This may reflect defects in subunit biogenesis or transport. Immunofluorescence microscopy in Hela cells overexpressing OGT shows nucleoplasmic fibrillarin puncta in contrast to nucleolar granular staining in controls. OGT overexpressing cells show disrupted nuclear staining of ribosomal protein (rp) L26, with abnormal nucleoplasmic granules and accumulation at the nuclear envelope. Under transmission electron microscopy the nucleus of cells with high OGT show low overall electron density with darker electron dense regions accumulating at the inner side of the nuclear envelope. Our results show that increased OGT disrupts fibrillarin and rpL26 nucleolar distribution suggesting a role for O‐GlcNAcylation in the maintenance of nucleolar organization and in the homeostasis of ribosomal subunits. Supported by NIH grants R01 DK61671 and R01 CA42486. Dr. Hart receives a share of royalty received by the university on sales of the CTD110.6 antibody. Terms of this arrangement are managed by JHU.