Localization of proteasomal antigens during different phases of the cell cycle in HeLa cells.
We localized two different proteasome-associated epitopes with the use of two specific monoclonal antibodies, MCP21 and anti-p25, in interphase and mitotic HeLa cells cultured in vitro. We provide evidence for an association of those antigens with the spindle poles in metaphase and with the midbody region in anaphase and telophase. Triton-nonextractable structures are also labeled in interphase. Moreover, the labeling pattern of interphase cells obtained with the monoclonal antibodies MCP21 and anti-p25 differs considerably, and in the case of MCP21 displays clear cell cycle-specific changes: nuclear labeling is absent or very weak in G1 and S phases of the cell cycle, whereas it is strong in G2 phase. This might reflect the existence of different subpopulations of proteasomes in the cell.
Wójcik
C
C
German Cancer Research Center, Division 0430, Heidelberg/Germany.
Paweletz
N
N
Schroeter
D
D
D000911:Antibodies, Monoclonal / Q000276:immunology; D002453:Cell Cycle; D002467:Cell Nucleus / Q000737:chemistry / Q000648:ultrastructure; D000090266:Chromobox Protein Homolog 5; D003546:Cysteine Endopeptidases / Q000032:analysis* / Q000276:immunology; D003902:Detergents / Q000494:pharmacology; D000939:Epitopes / Q000032:analysis / Q000276:immunology; D006367:HeLa Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology / Q000648:ultrastructure; D006801:Humans; D007399:Interphase; D008677:Metaphase; D008856:Microscopy, Fluorescence; D008938:Mitosis; D009097:Multienzyme Complexes / Q000032:analysis* / Q000276:immunology; D017830:Octoxynol / Q000494:pharmacology; D015388:Organelles / Q000648:ultrastructure*; D046988:Proteasome Endopeptidase Complex; D012995:Solubility; D008941:Spindle Apparatus / Q000737:chemistry / Q000648:ultrastructure
D000911:Antibodies, Monoclonal; C000715594:CBX5 protein, human; D003902:Detergents; D000939:Epitopes; D009097:Multienzyme Complexes; D000090266:Chromobox Protein Homolog 5; D017830:Octoxynol; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex