plant biology. For the article “CK2 phosphorylation of CCA1 is necessary for its circadian oscillator function in Arabidopsis,” by Xavier Daniel, Shoji Sugano, and Elaine M. Tobin, which appeared in issue 9, March 2, 2004, of Proc. Natl. Acad. Sci. USA (101, 3292–3297; first published February 20, 2004; 10.1073/pnas.0400163101), due to a printer's error, the bottom portion of the top band of Fig. 2B is not visible. The corrected figure and its legend appear below.

Fig. 2.

Unlike overexpression of CCA1, overexpression of mCCA1 does not abolish circadian rhythms in the central oscillator. Wild-type (filled triangles), CCA1-ox (filled squares), and mCCA1-ox (open circles, dotted line) plants were entrained in light/dark (LD) conditions (12 h of light/12 h of dark) and transferred to constant light (LL). Samples were collected every 4 h and submitted to RNA and protein extractions. (A) Expression of endogenous CCA1 measured by RT-PCR. The relative levels of endogenous CCA1 mRNA were normalized to the lowest value of the wild-type samples. Each reaction was performed three times from two independent experiments with similar results. (B) LHY protein levels in wild-type, CCA1-ox, and mCCA1-ox plants measured by Western blot. Pyrophosphatase (PPase) was used as a loading control. Experiments were performed two times with similar results. The solid arrows indicate the location of both LHY and PPase proteins. The dotted arrow indicates where LHY protein is expected in CCA1-ox plants. White and black bars indicate light and dark periods, respectively, in LD. The white and the hatched bars indicate light and subjective dark periods, respectively, in LL.