Figure 1.

Up-regulated Stra13 expression is associated with growth arrest. (A) P19 cells were treated with 1 μM RA for 0–24 h, and the expression of Stra13 and c-Myc was analyzed by Northern blot analysis. The amounts of RNA were normalized with 36B4 transcripts that are not altered upon RA treatment. (B) Asynchronized NIH 3T3 cells were treated with 1 μM TSA for 0–24 h, and the expression of Stra13 and c-Myc was analyzed by Western blot analysis. FACS analysis of control and TSA-treated cells (collected 12 h after TSA addition) confirmed that the cells are arrested in the G₂/M phase. (C) NIH 3T3 cells grown in 10% FCS were transferred to medium containing 0.1% FCS. Cell lysates were collected at the times indicated and subjected to Western blot analysis. FACS analysis confirmed that the cells are arrested in the G₁ and G₂/M phases of the cell cycle. (D) NIH 3T3 cells were cotransfected with either the empty vector (pCS2) or a Stra13 expression vector together with a puromycin resistance plasmid. After 14 days of selection with puromycin, the colonies were stained with crystal violet. (Left) Representative plates from two independent experiments. The mean colony numbers obtained with pCS2 vs. Stra13 are shown in the Center. (Right) Western blot analysis of cell lysates from vector- (pCS2) or Stra13-transfected samples collected 48 h after transfection, confirming that Stra13 was expressed in the transfected cells.