Activation of c-myb by carboxy-terminal truncation: relationship to transformation of murine haemopoietic cells in vitro.
Murine retroviruses which encode c-myb proteins that have either complete or truncated carboxy (C) termini were used to infect haemopoietic cells from murine fetal liver. Using an agar colony assay, we could show that infection with the virus encoding the truncated protein resulted in the persistence of colony-forming cells well beyond the short period for which such cells are present in uninfected cultures. The resultant colonies failed to give rise to cell lines; however, clonal cell lines occasionally emerged from the original infected liquid cultures. The virus which encoded a myb protein with a complete C-terminus was virtually inactive in the colony assay; surprisingly, however, this virus could enhance proliferation in liquid cultures and has led to the generation of at least one cell line. In addition to demonstrating 'activation' of c-myb by C-terminal truncation, our results imply that an unaltered c-myb protein can also contribute to cellular transformation and that a second event is required to establish myb-transformed cells as a permanent cell line.
Gonda
T J
TJ
Ludwig Institute for Cancer Research, Melbourne Tumour Biology Branch, Royal Melbourne Hospital, Victoria, Australia.
Buckmaster
C
C
Ramsay
R G
RG
D000818:Animals; D002461:Cell Line, Transformed; D003114:Colony-Forming Units Assay; D005786:Gene Expression Regulation; D006413:Hematopoietic System / Q000378:metabolism; D051379:Mice; D020626:Oncogene Proteins v-myb; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D020598:Proto-Oncogene Proteins c-myb; D012190:Retroviridae / Q000235:genetics; D012191:Retroviridae Proteins / Q000235:genetics
D020626:Oncogene Proteins v-myb; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D012191:Retroviridae Proteins