Corrections and Retraction CORRECTIONS RETRACTION CELL BIOLOGY MEDICAL SCIENCES Correction for “A small molecule accelerates neuronal differ- Retraction for “Wnt-5a signaling restores tamoxifen sensitivity in entiation in the adult rat,” by Heiko Wurdak, Shoutian Zhu, estrogen receptor-negative breast cancer cells,” by Caroline E. Kyung Hoon Min, Lindsey Aimone, Luke L. Lairson, James Ford, Elin J. Ekström, and Tommy Andersson, which appeared Watson, Gregory Chopiuk, James Demas, Bradley Charette, in issue 10, March 10, 2009, of Proc Natl Acad Sci USA Eranthie Weerapana, Benjamin F. Cravatt, Hollis T. Cline, Eric (106:3919–3924; first published February 23, 2009; 10.1073/ C. Peters, Jay Zhang, John R. Walker, Chunlei Wu, Jonathan pnas.0809516106). Chang, Tove Tuntland, Charles Y. Cho, and Peter G. Schultz, The authors wish to note the following: “During efforts to which appeared in issue 38, September 21, 2010, of Proc Natl extend this work, we re-examined the laboratory records for all Acad Sci USA (107:16542–16547; first published September 7, figures and found that the Excel files on which Fig. 4C was based 2010; 10.1073/pnas.1010300107). contained serious calculation errors; the first author of the paper The authors note that Rajkumar Halder should be added takes full responsibility for these inaccuracies. Considering the to the author line between Bradley Charette and Eranthie importance of this figure for the conclusions drawn, the authors Weerapana. Rajkumar Halder should be credited with contrib- hereby retract the work. We apologize for any inconvenience this uting new reagents/analytic tools. The online version has been may have caused.” corrected. The corrected author and affiliation lines, and author Caroline E. Ford contributions appear below. a,1 a,1 a,2 Elin J. Ekström Heiko Wurdak ,ShoutianZhu , Kyung Hoon Min ,Lindsey Tommy Andersson Aimoneb,LukeL.Lairsona, James Watsonb, Gregory Chopiukb, James Demasc,3, Bradley Charettea, Rajkumar Haldera, Eranthie www.pnas.org/cgi/doi/10.1073/pnas.1017549108 Weerapanaa,BenjaminF.Cravatta,HollisT.Clinec,EricC. Petersb, Jay Zhangb, John R. Walkerb,ChunleiWub,Jonathan Changb, Tove Tuntlandb, Charles Y. Chob, and Peter G. Schultza,4 aThe Skaggs Institute of Chemical Biology and Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037; bGenomics Institute of the Novartis Research Foundation, San Diego, CA 92121; and cDepartment of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037 Author contributions: H.W., S.Z., L.L.L., B.C., B.F.C., T.T., C.Y.C., and P.G.S. designed research; H.W., S.Z., K.H.M., L.A., L.L.L., J.W., G.C., E.W., E.C.P., J.Z., and J.C. performed research; K.H.M., G.C., R.H., and H.T.C. contributed new reagents/analytic tools; H.W., S.Z., L.L.L., J.D., B.C., E.C.P., J.R.W., C.W., T.T., and P.G.S. analyzed data; and H.W., S.Z., and P.G.S. wrote the paper. www.pnas.org/cgi/doi/10.1073/pnas.1016908108 GENETICS Correction for “SET DOMAIN GROUP2 is the major histone H3 lysie 4 trimethyltransferase in Arabidopsis,” by Lin Guo, Yanchun Yu, Julie A. Law, and Xiaoyu Zhang, which appeared in issue 43, October 26, 2010, of Proc Natl Acad Sci USA (107:18557–18562; first published October 11, 2010; 10.1073/pnas.1010478107). The authors note that, due to a printer’s error, the manuscript title “SET DOMAIN GROUP2 is the major histone H3 lysie 4 trimethyltransferase in Arabidopsis” should instead appear as “SET DOMAIN GROUP2 is the major histone H3 lysine 4 tri- methyltransferase in Arabidopsis.” The online version has been corrected. www.pnas.org/cgi/doi/10.1073/pnas.1016620107 22360 | PNAS | December 21, 2010 | vol. 107 | no. 51 www.pnas.org Downloaded by guest on September 23, 2021 SET DOMAIN GROUP2 is the major histone H3 lysie 4 trimethyltransferase in Arabidopsis Lin Guoa,1, Yanchun Yua,1, Julie A. Lawb, and Xiaoyu Zhanga,2 aDepartment of Plant Biology, University of Georgia, Athens, GA 30602; and bDepartment of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA 90095 Edited* by Susan Wessler, University of California, Riverside, CA, and approved September 8, 2010 (received for review July 19, 2010) Posttranslational modifications of histones play important roles in Understanding of the activities of individual HMTases is modulating chromatin structure and regulating gene expression. crucial for elucidating the mechanisms and functions of histone We have previously shown that more than two thirds of Arabi- methylation. More than 30 putative HMTase genes have been dopsis genes contain histone H3 methylation at lysine 4 (H3K4me) identified in the Arabidopsis genome (29–32). These genes are and that trimethylation of H3K4 (H3K4me3) is preferentially lo- named SET DOMAIN GROUP (SDG) genes because they con- cated at actively transcribed genes. In addition, several Arabidop- tain the SET lysine methyltransferase catalytic domain (named sis mutants with locus-specific loss of H3K4me have been found to after the Drosophila histone methyltransferases Su(var)3-9, En- display various developmental abnormalities. These findings sug- hancer-of-zeste, and Trithorax) (31). Previous phylogenetic anal- fi – gest that H3K4me3 may play important roles in maintaining the yses of plant SDGs have resolved ve ancient classes (classes I fi normal expression of a large number of genes. However, the ma- V) that have likely diverged before the diversi cation of plants, animals, and fungi, because all five classes also include animal jor enzyme(s) responsible for H3K4me3 has yet to be identified in fi plants, making it difficult to address questions regarding the and/or fungal proteins (31). In four of the ve classes, the plant SDGs seem to share similar enzymatic activities with their ani- mechanisms and functions of H3K4me3. Here we described the mal and/or fungal homologs. Specifically, class I SDGs are in- characterization of SET DOMAIN GROUP 2 (SDG2), a large Arabi- volved in H3K27me2/3, class II in H3K36me2/3, class III in dopsis protein containing a histone lysine methyltransferase do- H3K4me2/3, and class V in H3K9me2 (13, 19, 33, 34). Class IV main. We found that SDG2 homologs are highly conserved in seems to be an exception: the Arabidopsis proteins SDG15 and GENETICS plants and that the Arabidopsis SDG2 gene is broadly expressed SDG34 are responsible for H3K27me1 (24), but it is not clear during development. In addition, the loss of SDG2 leads to severe whether the two yeast homologs (SET3 and SET4) possess and pleiotropic phenotypes, as well as the misregulation of a large HMTase activity. The HMTases responsible for H3K4me1, number of genes. Consistent with our finding that SDG2 is a robust H3K9me1/3, and H3K36me1 have yet to be determined but are and specific H3K4 methyltransferase in vitro, the loss of SDG2 likely to be uncharacterized members in these five classes. leads to a drastic decrease in H3K4me3 in vivo. Taken together, Our previous genome-wide study of H3K4me in Arabidopsis these results suggest that SDG2 is the major enzyme responsible showed that more than two thirds of Arabidopsis genes contain at for H3K4me3 in Arabidopsis and that SDG2-dependent H3K4m3 is least one type of H3K4me and that actively transcribed genes are critical for regulating gene expression and plant development. usually associated with H3K4me3 (9). These findings suggest that H3K4me3 may play important roles in maintaining the chromatin | methylation proper expression levels of numerous genes. However, how H3K4me3 HMTases are recruited to individual genes and the exact function(s) of H3K4me3 remain poorly understood. This he nuclear DNA in eukaryotic cells is wrapped around his- largely reflects the fact that the major H3K4me3 HMTase has yet Ttone octamers (two copies each of H2A, H2B, H3, and H4) to be identified. Mutants in three of the seven class III HMTase to form nucleosomes, the basic units of chromatin. A myriad of genes (ATX1/SDG27, ATX2/SDG30, ATXR7/SDG25) display molecular processes, such as transcription, replication, DNA locus-specific defects in H3K4me; however, the global levels of repair, and recombination, take place in a chromatin environ- H3K4me3 in these mutants remain similar to that of wild type (25, ment and therefore can be profoundly affected by chromatin 26, 28, 35). structure. A growing body of evidence from recent studies indi- Here we describe the characterization of SDG2, a large and cates that posttranslational covalent modifications of histones structurally unique protein belonging to class III. SDG2 shares play important roles in modulating the structural properties of no significant sequence homology with other Arabidopsis SDGs chromatin. Four types of histone modifications have been de- outside of the SET domain. However, we found that SDG2 scribed in plants, namely methylation, acetylation, phosphoryla- homologs are widespread and highly conserved in plants and that tion, and ubiquitination (1, 2). Adding to the complexity of SDG2 is broadly expressed during Arabidopsis development. In histone modifications is the finding that at least two dozen res- addition, the loss of SDG2 leads to severe and pleiotropic phe- idues in core histones can be modified (1). notypes and the misregulation of numerous genes. Furthermore, fi Four lysine residues in Arabidopsis core histones can be meth- SDG2 displays robust and speci c H3K4me1, H3K4me2, and ylated, specifically, histone H3 lysine4 (H3K4), H3K9, H3K27, and H3K4me3 HMTase activities in vitro. Finally, the loss of SDG2 H3K36 (1). Results from recent genome-scale profiling studies suggest that most Arabidopsis genes contain methylated histones and that different types of methylation are preferentially associ- Author contributions: L.G., Y.Y., and X.Z. designed research; L.G., Y.Y., and J.A.L. per- ated with different transcription states (3–11). That is, actively formed research; L.G., Y.Y., and X.Z.