The U6 Biogenesis-Like 1 Plays an Important Role in Maize Kernel and Seedling Development by Affecting the 3' End Processing of U6 snRNA.
Regulation of gene expression at the post-transcriptional level is of crucial importance in the development of an organism. Here we present the characterization of a maize gene, U6 biogenesis-like 1 (UBL1), which plays an important role in kernel and seedling development by influencing pre-mRNA splicing. The ubl1 mutant, exhibiting small kernel and weak seedling, was isolated from a Mutator-tagged population. Transgenic complementation and three independent mutant alleles confirmed that UBL1, which encodes a putative RNA exonuclease belonging to the 2H phosphodiesterase superfamily, is responsible for the phenotype of ubl1. We demonstrated that UBL1 possess the RNA exonuclease activity in vitro and found that loss of UBL1 function in ubl1 causes decreased level and abnormal 3' end constitution of snRNA U6, resulting in splicing defect of mRNAs. Through the in vitro and in vivo studies replacing two histidines with alanines in the H-X-T/S-X (X is a hydrophobic residue) motifs we demonstrated that these two motifs are essential for the normal function of UBL1. We further showed that the function of UBL1 may be conserved across a wide phylogenetic distance as the heterologous expression of maize UBL1 could complement the Arabidopsis ubl1 mutant.
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences.
Jiankun
J
Li
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Junjie
J
Fu
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Yan
Y
Chen
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Kaijian
K
Fan
Center of Seed Science and Technology, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
Cheng
C
He
Center of Seed Science and Technology, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
Zhiqiang
Z
Zhang
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Li
L
Li
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Yunjun
Y
Liu
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Jun
J
Zheng
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences.
Dongtao
D
Ren
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: wangguoying@caas.cn.
Guoying
G
Wang
D007438:Introns / Q000235:genetics; D012326:RNA Splicing / Q000235:genetics; D012342:RNA, Small Nuclear / Q000235:genetics*; D036226:Seedlings / Q000235:genetics*; D003313:Zea mays / Q000235:genetics*
D012342:RNA, Small Nuclear; C405486:U6 small nuclear RNA
RNA splicing; U6 snRNA; UBL1; intron retention; kernel development; maize