Kringle Containing Transmembrane Protein 1 (KREMEN1)

Kremen protein 1 is a high-affinity dickkopf homolog 1 (DKK1) transmembrane receptor that functionally cooperates with DKK1 to block wingless (WNT)/beta-catenin signaling. The deduced 473-amino acid protein contains an N-terminal signal sequence, followed by a kringle domain, a WSC domain, a CUB domain, a transmembrane domain, and an intracellular C-terminal tail. Northern blot analysis detected a 5.0-kb transcript in all mouse tissues examined, with highest expression in heart, lung, kidney, and skeletal muscle. In addition, testis expressed transcripts of 3.0 and 2.3 kb. Krm1 expression was detected in the apical ectodermal ridge of limb buds, myotome, and sensory organs of mouse embryos and increased during development. Krm1 expression increased during differentiation in mouse myoblast and neuroblastoma cell lines.