Molecular cloning of crtc2 and its expression in response to different feeding status in largemouth bass (Micropterus salmoides)

Abstract

Crtc2, a member of the cAMP response element-binding protein (CREB)-regulated transcription coactivators family, plays crucial roles in variety of cellular functions and biological processes, including energy homeostasis, immunity, and endoplasmic reticulum (ER) stress in mammals. Thus far, its roles in teleosts are still rarely known. In the present study, the crtc2 gene was identified and characterized from largemouth bass (Micropterus salmoides), and then its transcription pattern in response to different feeding status was determined. The coding sequence of crtc2 gene is 2565 bp in length, encoding a protein with 854 amino acids. The putative Ms-crtc2 contains a typical N-terminal CREB-binding domain (CBD), a central regulatory domain (REG), a C-terminal transactivation domain (TAD), as well as conserved 14–3–3 binding sites, SIK2 and AMPK phosphorylation sites. Multiple alignments revealed that Ms-crtc2 shares high identity with its homologs in teleosts. Phylogenetic, syntenic, and gene structure analysis further demonstrated that crtc2 genes are highly conserved among vertebrates. Meanwhile, Ms-crtc2 was detectable in all tested tissues with the highest expression level in spleen. In a long-term fasting and refeeding experiment, we found that the transcriptional level of crtc2 was significantly increased during starvation, and then returned to normal level after refeeding in all tested tissues. Taken together, our findings reveal that the crtc2 gene may play important roles in regulating energy homeostasis and immune response in largemouth bass, which should be beneficial for further studies on the function of crtc2 in teleosts.

Keywords

• Crtc2
• Micropterus salmoides
• Tissue expression
• Fasting
• Refeeding