Kremen protein 1 is a protein that in humans is encoded by the KREMEN1gene.[5][6]Kremen1 is conserved in chordates including amphioxus[7] and most vertebrate species.[8] The protein is a type I transmembrane receptor of ligands Dickkopf1,[9] Dickkopf2, Dickkopf3, Dickkopf4, EpCAM[10] and Rspondin1.
This gene encodes a high-affinity dickkopf homolog 1 (DKK1) transmembrane receptor that functionally cooperates with DKK1 to block wingless (WNT)/beta-catenin signaling. The encoded protein is a component of a membrane complex that modulates canonical WNT signaling through lipoprotein receptor-related protein 6 (LRP6). It contains extracellular Kringle, WSC, and CUB domains. Alternatively spliced transcript variants encoding distinct isoforms have been observed for this gene.[6]
Kremen1 also has a function in the induction of cell death by apoptosis.[8] This proapototic activity is conditional and depends on the absence of ligand Dickkopf1.[8] These observations led to the classification of this protein as a Dependence Receptor.
A mouse knock out of Kremen1 and its paralog Kremen2 is viable and fertile.[11]
^Zhang, Yujun; Mao, Bingyu (2010-09-01). "Embryonic expression and evolutionary analysis of the amphioxus Dickkopf and Kremen family genes". Journal of Genetics and Genomics = Yi Chuan Xue Bao. 37 (9): 637–645. doi:10.1016/S1673-8527(09)60082-5. ISSN1673-8527. PMID20933216.
Brandenberger R, Wei H, Zhang S, et al. (2005). "Transcriptome characterization elucidates signaling networks that control human ES cell growth and differentiation". Nat. Biotechnol. 22 (6): 707–16. doi:10.1038/nbt971. PMID15146197. S2CID27764390.