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Proteasome response to interferon‐γ is altered in senescent human fibroblasts
Author(s) -
Stratford Fiona L.L.,
Chondrogianni Niki,
Trougakos Ioannis P.,
Gonos Efstathios S.,
Rivett A. Jennifer
Publication year - 2006
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2006.06.029
Subject(s) - proteasome , microbiology and biotechnology , regulator , interferon , senescence , biology , cell growth , cell , chemistry , biochemistry , immunology , gene
We have investigated immunoproteasomes in human fibroblasts during replicative senescence. Unlike levels of constitutive proteasome catalytic subunits and 26S proteasome regulatory subunits, levels of immunosubunits did not decrease dramatically in senescent cells. However, the induction of immunosubunits by interferon‐γ (IFN‐γ) was lost in senescent cells. In contrast, levels of the 11S proteasome regulator, PA28, were increased by IFN‐γ even in senescent cells, and both immunosubunits and PA28 increased with the reversible growth arrest in confluent cell cultures. The results highlight differences in the mechanisms of regulation of immunoproteasomes compared to constitutive proteasomes and in the irreversible growth arrest of senescent cells compared to reversible contact‐induced growth arrest.