Characterization of proliferating cell nuclear antigen (PCNA) isoforms in normal and cancer cells: there is no cancer-associated form of PCNA.
In order to clarify the status of PCNA in normal and transformed cells, we performed analysis of this protein by 2D-PAGE, Western blot and mass spectrometry. All the cell lines examined contained the major PCNA form (pI 4.57/30kDa), that is not post-translationally modified. In addition to the major form, two minor isoforms (pI 4.52/30kDa and pI 4.62/30kDa) were also detected in all the cell lines examined. However, the level of PCNA in cancer cells is 5-6 folds higher than those in primary and most of the immortalized cells. Taken together, the significant difference in PCNA status between cancer and normal cells is not at the post-translational modifications but in the overall levels of PCNA.
Naryzhny
Stanislav N
SN
Tumour Biology Group, Northeastern Ontario Regional Cancer Program at the Sudbury Regional Hospital, 41 Ramsey Lake Road, Sudbury, Ontario, Canada P3E 5J1. snaryzhny@hrsrh.on.ca
Lee
Hoyun
H
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D045744:Cell Line, Tumor; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000737:chemistry / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D020033:Protein Isoforms / Q000032:analysis; D011499:Protein Processing, Post-Translational
D018809:Proliferating Cell Nuclear Antigen; D020033:Protein Isoforms