Identification and functional analysis of Zranb2 as a novel Smad-binding protein that suppresses BMP signaling

Satoshi Ohte, Shoichiro Kokabu, Shun Ichiro Iemura, Hiroki Sasanuma, Katsumi Yoneyama, Masashi Shin, Seiya Suzuki, Toru Fukuda, Yukio Nakamura, Eijiro Jimi, Toru Natsume, Takenobu Katagiri

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13 Citations (Scopus)

Abstract

Smads 1/5/8 transduce the major intracellular signaling of bone morphogenetic proteins (BMPs). In the present study, we analyzed Smad1- binding proteins in HEK293T cells using a proteomic technique and identified the protein, zinc-finger, RAN-binding domain-containing protein 2 (ZRANB2). Zranb2 interacted strongly with Smad1, Smad5, and Smad8 and weakly with Smad4. The overexpression of Zranb2 inhibited BMP activities in C2C12 myoblasts in vitro, and the injection of Zranb2 mRNA into zebrafish embryos induced weak dorsalization. Deletion analyses of Zranb2 indicated that the serine/arginine-rich (SR) domain and the glutamine-rich domain were required for the inhibition of BMP activity and the interaction with Smad1, respectively. Zranb2 was found to be localized in the nucleus; however, the SR domain-deleted mutant localized to the cytoplasm. The knockdown of endogenous Zranb2 in C2C12 cells enhanced BMP activity. Zranb2 suppressed Smad transcriptional activity without affecting Smad phosphorylation, nuclear localization, or DNA binding. Taken together, these findings suggested that Zranb2 is a novel BMP suppressor that forms a complex with Smads in the nucleus.

Original languageEnglish
Pages (from-to)808-814
Number of pages7
JournalJournal of Cellular Biochemistry
Volume113
Issue number3
DOIs
Publication statusPublished - Mar 1 2012
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Ohte, S., Kokabu, S., Iemura, S. I., Sasanuma, H., Yoneyama, K., Shin, M., ... Katagiri, T. (2012). Identification and functional analysis of Zranb2 as a novel Smad-binding protein that suppresses BMP signaling. Journal of Cellular Biochemistry, 113(3), 808-814. https://doi.org/10.1002/jcb.23408