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O‐glycosylation regulates H‐ferritin transport into the nucleus
Author(s) -
Geguchadze Ramaz N,
Surgaldze Nodar M,
Zhang Xuesheng,
Weston Holly R,
Connor James R
Publication year - 2007
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.21.6.a990-a
Subject(s) - ferritin , cytosol , nucleus , glycosylation , cytoplasm , chemistry , chromosomal translocation , western blot , transport protein , biochemistry , cell nucleus , microbiology and biotechnology , biology , gene , enzyme
Ferritin, the cytoplasmic iron storage protein, has been observed in cell nuclei by a number of different groups. Ferritin consists of two subunits (H and L) and H‐ferritin is primary form of ferritin in the nucleus. We previously demonstrated that O‐linked glycosylation was required for translocation of H‐ferritin from cytosol to nucleus. This study focuses on the mechanism responsible for nuclear transport of ferritin, specifically the requirement for N‐termini O‐glycosylation in H‐ferritin transport. H‐ferritin constructs were produced with N, C or both N and C termini truncations. In addition, the truncated sequences were added to L‐ferritin creating three additional constructs. These alterations allow L‐ferritin expression of O‐glycosylation sites normally observed in H‐ferritin. Primary rat astrocytes were nucleofected with the constructs and then processed to separate nuclear and cytosol fractions. Western blot analysis revealed nuclear localization for H‐ferritin constructs expressing the N‐termini portion of H‐ferritin, and a corollary decrease in H‐ferritin presence in the nucleus by N‐termini truncated constructs. In addition, L‐ferritin constructs expressing the N‐termini portion of H‐ferritin were detected in the nucleus. In conclusion, H‐ferritin translocation into the nucleus is regulated by the presence of O‐glycosylation sites located within the N‐termini.