Domain structure and conserved features of CTRP12.
A, four domains of CTRP12 protein: a signal peptide (SP); an N-terminal domain with the highly conserved N-glycosylation site (Asn39), Cys85, and polybasic cleavage motif KKXR; a collagen domain with six Gly-X-Y repeats; and a globular C1q/TNF-like domain with three conserved Cys residues (Cys162, Cys241, and Cys246) and two potential N-glycosylation sites (Asn287 and Asn297). Endopeptidase cleavage at Lys91 (indicated by arrow) generates the gCTRP12 isoform. B, sequence alignment of mouse, human, chicken, Xenopus, and zebra fish CTRP12. Highlighted are the conserved Asn39 shown to be glycosylated in this study, the cleavage motif KKXR, and the Cys85 shown in this study to be important for disulfide-linked multimerization of CTRP12.