The Arabidopsis homolog of human minor spliceosomal protein U11-48K plays a crucial role in U12 intron splicing and plant development.
The minor U12 introns are removed from precursor mRNAs by the U12 intron-specific minor spliceosome. Among the seven ribonucleoproteins unique to the minor spliceosome, denoted as U11/U12-20K, U11/U12-25K, U11/U12-31K, U11/U12-65K, U11-35K, U11-48K, and U11-59K, the roles of only U11/U12-31K and U11/U12-65K have been demonstrated in U12 intron splicing and plant development. Here, the functional role of the Arabidopsis homolog of human U11-48K in U12 intron splicing and the development of Arabidopsis thaliana was examined using transgenic knockdown plants. The u11-48k mutants exhibited several defects in growth and development, such as severely arrested primary inflorescence stems, formation of serrated leaves, production of many rosette leaves after bolting, and delayed senescence. The splicing of most U12 introns analyzed was impaired in the u11-48k mutants. Comparative analysis of the splicing defects and phenotypes among the u11/u12-31k, u11-48k, and u11/12-65k mutants showed that the severity of abnormal development was closely correlated with the degree of impairment in U12 intron splicing. Taken together, these results provide compelling evidence that the Arabidopsis homolog of human U11-48K protein, as well as U11/U12-31K and U11/U12-65K proteins, is necessary for correct splicing of U12 introns and normal plant growth and development.
College of Life Science, Jiangsu Normal University, Xuzhou 221116, Jiangsu Province, PR China.
Tao
T
Xu
Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, South Korea.
Bo Mi
BM
Kim
Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, South Korea.
Kyung Jin
KJ
Kwak
Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, South Korea.
Hyun Ju
HJ
Jung
Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, South Korea hskang@jnu.ac.kr.
Hunseung
H
Kang
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D007438:Introns; D012326:RNA Splicing / Q000235:genetics; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics* / Q000378:metabolism
D029681:Arabidopsis Proteins; D017411:Ribonucleoproteins, Small Nuclear; C552126:U11-U12 small nuclear ribonucleoprotein
Arabidopsis thaliana; U11-48K.; U12 intron; minor spliceosome; plant development; splicing