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Evidence for distinct functions for human DNA repair factors hHR23A and hHR23B
Author(s) -
Chen Li,
Madura Kiran
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.2006.05.012
Subject(s) - proteasome , ubiquitin , threonine , biochemistry , dna repair , proteolysis , dna , dna binding protein , microbiology and biotechnology , chemistry , biology , enzyme , transcription factor , gene , serine
Rad23 proteins bind ubiquitinated substrates and the proteasome, consistent with an important role in protein degradation. Although human Rad23 proteins (hHR23A and hHR23B) have redundant roles in DNA repair, we determined they formed distinct interactions with proteasomes and multiubiquitinated proteins, but similar binding to Ataxin‐3. Threonine‐79 contributed to the weak proteasome‐binding property of hHR23A, and its conversion to proline (T79P), which is the residue present in hHR23B, increased proteasome interaction. We also determined that hHR23A and hHR23B could be co‐purified with unique proteolytic and stress‐responsive factors from human breast cancer tissues, indicating that they have unique functions in vivo.