Cyclin mRNA and protein expression in recombinant interleukin 2-stimulated cloned murine T lymphocytes.
Expression of cyclin, a non-histone nuclear protein, during recombinant interleukin 2 (rIL2)-driven cell-cycle progression of cloned T lymphocytes has been assessed. We found that expression of cyclin protein, as detected by immunofluorescence, is tightly associated with proliferation, and not merely S-phase, of L2 cells stimulated with rIL2. Cyclin immunofluorescence was detected in all cell-cycle phases (G1/S/G2/M, as detected by flow cytometry) of proliferating L2 cells. Accumulation of cyclin mRNA levels was induced as early as 1 h after stimulation, was maximal at 25-49 h, and remained elevated throughout stimulation, as detected by Northern blot analysis. A cDNA-encoding murine cyclin was cloned from a cDNA library prepared from IL2-stimulated cloned T cells. The sequence of the 5' end of the murine cyclin cDNA was determined and found to be 88% and 82% similar to the sequences of cDNA clones encoding rat and human cyclin, respectively. The present studies demonstrate that cyclin protein and mRNA accumulation are highly regulated during IL2-induced proliferation of a cloned T cell. These data provide a framework for addressing the molecular mechanisms regulating cyclin gene expression during cellular proliferation.
Shipman
P M
PM
Department of Pathology, University of Pennsylvania, Philadelphia 19104-6082.
Sabath
D E
DE
Fischer
A H
AH
Comber
P G
PG
Sullivan
K
K
Tan
E M
EM
Prystowsky
M B
MB
D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle; D002455:Cell Division; D004247:DNA / Q000096:biosynthesis*; D005786:Gene Expression Regulation; D007376:Interleukin-2 / Q000494:pharmacology; D009687:Nuclear Proteins / Q000032:analysis / Q000096:biosynthesis*; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D011994:Recombinant Proteins; D013045:Species Specificity; D013601:T-Lymphocytes
D007376:Interleukin-2; D009687:Nuclear Proteins; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D011994:Recombinant Proteins; D004247:DNA