The Coiled‐Coil Domain Containing 80 (ccdc80) Gene Regulates gadd45β2 Expression in the Developing Somites of Zebrafish as a New Player of the Hedgehog Pathway

Abstract

The Coiled-Coil Domain Containing 80 (CCDC80) gene has been identified as strongly induced in rat thyroid PC CL3 cells immortalized by the adenoviral E1A gene. In human, CCDC80 is a potential oncosoppressor due to its down-regulation in several tumor cell lines and tissues and it is expressed in almost all tissues. CCDC80 has homologous in mouse, chicken, and zebrafish. We cloned the zebrafish ccdc80 and analyzed its expression and function during embryonic development. The in-silico translated zebrafish protein shares high similarity with its mammalian homologous, with nuclear localization signals and a signal peptide. Gene expression analysis demonstrates that zebrafish ccdc80 is maternally and zygotically expressed throughout the development. In particular, ccdc80 is strongly expressed in the notochord and it is under the regulation of the Hedgehog pathway. In this work we investigated the functional effects of ccdc80-loss-of-function during embryonic development and verified its interaction with gadd45β2 in somitogenesis.

DRO1/CCDC80: a Novel Tumor Suppressor of Colorectal Carcinogenesis

“…In the developing zebrafish, knockdown of Dro1/Ccdc80 by injection of morpholino impairs somite formation and correlates with significant downregulation of the cell cycle regulator gadd45β2 [21]. Consistently, treatment of embryos with gadd45β2 mRNA partially rescues the Dro1/Ccdc80 knockdown phenotype, and overexpression of Dro1/Ccdc80 induces gadd45β2 expression, suggesting gadd45β2 to be a potential downstream effector of Dro1/Ccdc80 [21].…”

“…Dro1/Ccdc80 has been described to be expressed in both adult and embryo [3••, 4, 8-11, 19, 24-26]. Ubiquitous tissue distribution has also been observed for the zebrafisch; however, here, maximum expression locates to the heart [21]. In rat and mouse, Dro1/Ccdc80 is expressed as a single transcript [8,25].…”

“…In the developing zebrafish expression of Dro1/Ccdc80 and Ccdc80-like1, a gene which displays 44 % sequence identity with human DRO1/CCDC80, has been shown to be positively regulated by the Hedgehog pathway [17,21]. Here, Dro1/Ccdc80 as well as Ccdc80-like1 became significantly downregulated after experimental or genetic inhibition of the Hedgehog signaling cascade, indicating a role as downstream targets of this pathway [17,21].…”

“…Here, Dro1/Ccdc80 as well as Ccdc80-like1 became significantly downregulated after experimental or genetic inhibition of the Hedgehog signaling cascade, indicating a role as downstream targets of this pathway [17,21].…”

“…Independently, sequences of the coding region of mouse Dro1/Ccdc80 have been cloned as an estrogen-regulated gene, steroid-sensitive gene 1 (SSG1), from rat uterus and mammary gland [9], as URB (upregulated in bombesin receptor subtype-3 (BRS-3)-deficient mice) from adipose tissue of obese BRS-3-deficient mice [19], cloned as CL2 (clone 2) from rat thyroid PC CL3 cells following transformation by the adenovirus E1A gene [8], and as Equarin from the chicken embryonic lens [11]. O'Leary et al recloned Dro1/Ccdc80 alias SSG1/Ccdc80 from a rat adipose cDNA library [20•], and recently, molecular cloning of the zebrafish Dro1/Ccdc80 homolog has been obtained [21]. The DRO1/CCDC80 amino acid sequence displays three internal repeats, termed DUDES repeat, which are highly similar to the C-terminal region of sushi-repeat protein on the Xchromosome (SRPX) and sushi-repeat protein upregulated in leukemia (SRPUL) and might therefore constitute a conserved functionally important region [4, 8, 11, 19, 20•].…”