C3-induced 3LL cell proliferation is mediated by C kinase.
It has been demonstrated that the third component of complement (C3)(1) and its peptides increase normal and tumour cell proliferation. However, the signal cascade responsible for this phenomenon is still unknown. In this study, we elucidate some of the mechanisms involved in the signalling of C3 stimulation of cell proliferation. We have first investigated the in and out traffic of C3 peptides, then we have identified the subcellular localisation of internalised C3 and, finally, we have explored the role of protein phosphorylation in C3 traffic and in the proliferation of the Lewis lung carcinoma (3LL) cells. Our results indicate that traffic of C3 is not dependent on cytoskeletal integrity and requires protein kinase C-dependent phosphorylation. In addition, proliferation of 3LL cells stimulated by C3 depends on both C3 internalisation and protein-kinase C phosphorylation.
Longo
Agostina
A
Department of Experimental Medicine and Pathology, La Sapienza University, Viale Regina Elena, 324 00161 Roma, Italy.
Gradini
Roberto
R
Mattei
Vincenzo
V
Morgante
Emanuela
E
Sale
Patrizio
P
Tafani
Marco
M
Lipari
Marcella
M
Pontieri
Giuseppe M
GM
Russo
Matteo A
MA
D000818:Animals; D049109:Cell Proliferation; D003176:Complement C3 / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D011493:Protein Kinase C / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism
D003176:Complement C3; D011493:Protein Kinase C