Substantial CCT activity is required for cell cycle progression and cytoskeletal organization in mammalian cells.
The chaperonin CCT hexadecamer is required for the folding of non-native actins and tubulins in eukaryotic cells. Among the consequences of greatly reducing CCT holocomplex levels in human cell lines by siRNA targeting are growth arrest and changes in cell morphology and motility. Less extensive reduction of CCT activity via microinjection of an inhibitory anti-CCT epsilon subunit monoclonal antibody, which alters the rates of substrate processing by CCT in vitro, causes a delay in cell cycle progression through G1/S phase in synchronized Swiss 3T3 cells. The degree of growth arrest strongly correlates with the extent of CCT depletion, indicating that full CCT activity is required for normal cell growth and division. Depletion of CCT does not affect actin polypeptide synthesis but causes a reduction in levels of native actin and perturbation of actin-based cell motility in BE cells. There are no large-scale effects on cytoplasmic protein synthesis or a general heat shock response during periods of low CCT activity.
Grantham
Julie
J
Cancer Research UK Centre for Cell and Molecular Biology, Chester Beatty Laboratories, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK. julie.grantham@molbio.gu.se
Brackley
Karen I
KI
Willison
Keith R
KR
D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000096:biosynthesis / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017209:Apoptosis / Q000502:physiology; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D019927:Cyclin E / Q000096:biosynthesis; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008870:Microtubules / Q000378:metabolism; D014176:Protein Biosynthesis / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D041701:Swiss 3T3 Cells; D014404:Tubulin / Q000096:biosynthesis / Q000378:metabolism; D000097869:Polo-Like Kinase 1
D000199:Actins; D000911:Antibodies, Monoclonal; D018797:Cell Cycle Proteins; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins; D019927:Cyclin E; D018841:HSP90 Heat-Shock Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D014404:Tubulin; D000097869:Polo-Like Kinase 1; C533301:CCT5 protein, human; C533315:Tcp1 protein, mouse