Natural antisense transcript TPM1-AS regulates the alternative splicing of tropomyosin I through an interaction with RNA-binding motif protein 4

Guo-Wei Huang; Ying-Li Zhang; Lian-Di Liao; En-Min Li; Li-Yan Xu

doi:10.1016/j.biocel.2017.07.017

Natural antisense transcript TPM1-AS regulates the alternative splicing of tropomyosin I through an interaction with RNA-binding motif protein 4

Int J Biochem Cell Biol. 2017 Sep:90:59-67. doi: 10.1016/j.biocel.2017.07.017. Epub 2017 Jul 25.

Authors

Guo-Wei Huang¹, Ying-Li Zhang², Lian-Di Liao³, En-Min Li⁴, Li-Yan Xu⁵

Affiliations

¹ Institute of Oncologic Pathology, Shantou University Medical College, Shantou, Guangdong, 515041, PR China; The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, Guangdong, 515041, PR China; Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou, Guangdong, 515041, PR China.
² Institute of Oncologic Pathology, Shantou University Medical College, Shantou, Guangdong, 515041, PR China; Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou, Guangdong, 515041, PR China.
³ Institute of Oncologic Pathology, Shantou University Medical College, Shantou, Guangdong, 515041, PR China; The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, Guangdong, 515041, PR China.
⁴ The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, Guangdong, 515041, PR China; Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou, Guangdong, 515041, PR China. Electronic address: nmli@stu.edu.cn.
⁵ Institute of Oncologic Pathology, Shantou University Medical College, Shantou, Guangdong, 515041, PR China; The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou, Guangdong, 515041, PR China. Electronic address: lyxu@stu.edu.cn.

PMID: 28754317
DOI: 10.1016/j.biocel.2017.07.017

Abstract

LncRNAs play a vital role in alternative splicing of target genes. However, the mechanisms underlying lncRNAs involvement in splicing are poorly understood. In the present study, we identified a previously uncharacterized lncRNA, which is denoted as TPM1-AS, is reverse-transcribed from the fourth intronic region of the tropomyosin I (TPM1). In situ hybridization and RNA immunoprecipitation assays demonstrated that TPM1-AS was located in the nucleus and interacted with RNA-binding motif protein 4 (RBM4) in human esophageal cancer cells. TPM1-AS overexpression or RBM4 knockdown decreased endogenous exon 2a expression of TPM1, resulting in specifically down-regulation of TPM1variant V2 and V7 in human esophageal cancer cells. Mechanismly, the interaction of TPM1-AS with RBM4 hindered binding of RBM4 to TPM1 pre-mRNA and inhibited RBM4 to promote endogenous exon 2a inclusion of TPM1. Importantly, overexpression of TPM1-AS inhibited migration and filopodium formation, whereas TPM1variant V2 and V7 promoted these behaviors of human esophageal cancer cells. Taken together, the results suggest that a natural antisense TPM1-AS regulates the alternative splicing of TPM1 through an interaction with RBM4 and involves in TPM1-mediated filopodium formation and migration of cancer cells.

Keywords: Alternative splicing; Exon 2a; RBM4; TPM1; TPM1-AS.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Alternative Splicing*
Cell Line, Tumor
Cell Nucleus / metabolism
Esophageal Neoplasms / pathology
Exons / genetics
Humans
Protein Binding
Pseudopodia / metabolism
RNA, Antisense / genetics*
RNA-Binding Proteins / metabolism*
Tropomyosin / genetics*

Substances

RBM4 protein, human
RNA, Antisense
RNA-Binding Proteins
TPM1 protein, human
Tropomyosin