Mouse TonEBP-NFAT5: expression in early development and alternative splicing

• Published in: American journal of physiology. Renal physiology Vol. 282; no. 5; p. F802
• Main Authors: Maouyo, Djikolngar, Kim, Jee Y, Lee, Sang D, Wu, Yanhong, Woo, Seung K, Kwon, Hyug M
• Format: Journal Article
• Language: English
• Published: United States 01-05-2002
• Subjects: Alternative Splicing; Amino Acid Sequence; Animals; Animals, Newborn - metabolism; Brain - embryology; Brain Chemistry; Cloning, Molecular; COS Cells; Embryo, Mammalian - chemistry; Gene Expression; Gestational Age; Heart - embryology; Humans; Liver - chemistry; Liver - embryology; Mice; Molecular Sequence Data; Myocardium - chemistry; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - analysis; Sequence Alignment; Spinal Cord - chemistry; Spinal Cord - embryology; Trans-Activators - chemistry; Trans-Activators - genetics; Trans-Activators - physiology; Transcription Factors; Transfection
• ISSN: 1931-857X
• DOI: 10.1152/ajprenal.00123.2001

Tonicity-responsive enhancer binding protein (TonEBP)- nuclear factor of activated T cell family 5 is a DNA binding protein that plays a key role in the response of cells to hypertonicity. However, TonEBP is expressed and active in tissues that are in an isotonic milieu. To explore the biological role of TonEBP, we cloned mouse TonEBP that shares 92% of amino acids with the human counterpart. TonEBP is expressed in embryonic stem cells and throughout the stages of fetal development. Immunohistochemical analysis shows expression of TonEBP in most, if not all, developing tissues, including the brain, colon, heart, muscle, and eyes. Widespread alternative splicing in exons 2-4 was detected throughout development and in different adult tissues. As a result, four different polypeptides are produced with different lengths at the NH(2) terminus. Two of the isoforms differ in their ability to stimulate transcription. In conclusion, the presence of TonEBP mRNA during mouse embryogenesis suggests that TonEBP functions at all stages of mouse development, as well as in isotonic adult tissues.