{{Short description|Protein-coding gene in the species Homo sapiens}} {{Infobox gene}} '''Kremen protein 1''' is a protein that in humans is encoded by the ''KREMEN1'' gene.<ref name="pmid11267660">{{cite journal |vauthors=Nakamura T, Aoki S, Kitajima K, Takahashi T, Matsumoto K, Nakamura T | title = Molecular cloning and characterization of Kremen, a novel kringle-containing transmembrane protein | journal = Biochim Biophys Acta | volume = 1518 | issue = 1–2 | pages = 63–72 |date=Mar 2001 | pmid = 11267660 | doi = 10.1016/s0167-4781(01)00168-3}}</ref><ref name="entrez">{{cite web | title = Entrez Gene: KREMEN1 kringle containing transmembrane protein 1| url = https://www.ncbi.nlm.nih.gov/gene?Db=gene&Cmd=ShowDetailView&TermToSearch=83999}}</ref> ''Kremen1'' is conserved in chordates including amphioxus<ref>{{Cite journal|last1=Zhang|first1=Yujun|last2=Mao|first2=Bingyu|date=2010-09-01|title=Embryonic expression and evolutionary analysis of the amphioxus Dickkopf and Kremen family genes|journal=Journal of Genetics and Genomics = Yi Chuan Xue Bao|volume=37|issue=9|pages=637–645|doi=10.1016/S1673-8527(09)60082-5|issn=1673-8527|pmid=20933216}}</ref> and most vertebrate species.<ref name=":0" /> The protein is a type I transmembrane receptor of ligands Dickkopf1,<ref>{{Cite journal|last1=Mao|first1=Bingyu|last2=Wu|first2=Wei|last3=Davidson|first3=Gary|last4=Marhold|first4=Joachim|last5=Li|first5=Mingfa|last6=Mechler|first6=Bernard M.|last7=Delius|first7=Hajo|last8=Hoppe|first8=Dana|last9=Stannek|first9=Peter|date=2002-06-06|title=Kremen proteins are Dickkopf receptors that regulate Wnt/beta-catenin signalling|journal=Nature|volume=417|issue=6889|pages=664–667|doi=10.1038/nature756|issn=0028-0836|pmid=12050670|bibcode=2002Natur.417..664M|s2cid=4418943}}</ref> Dickkopf2, Dickkopf3, Dickkopf4, EpCAM<ref>{{Cite journal|last1=Lu|first1=Huiqiang|last2=Ma|first2=Jun|last3=Yang|first3=Yun|last4=Shi|first4=Wenchao|last5=Luo|first5=Lingfei|date=2013-03-11|title=EpCAM is an endoderm-specific Wnt derepressor that licenses hepatic development|journal=Developmental Cell|volume=24|issue=5|pages=543–553|doi=10.1016/j.devcel.2013.01.021|issn=1878-1551|pmid=23484855|doi-access=free}}</ref> and Rspondin1.
== Function == 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.<ref name="entrez" />
Kremen1 also has a function in the induction of cell death by apoptosis.<ref name=":0">{{Cite journal|last1=Causeret|first1=F.|last2=Sumia|first2=I.|last3=Pierani|first3=A.|date=2016-02-01|title=Kremen1 and Dickkopf1 control cell survival in a Wnt-independent manner|journal=Cell Death and Differentiation|volume=23|issue=2|pages=323–332|doi=10.1038/cdd.2015.100|issn=1476-5403|pmc=4716294|pmid=26206087}}</ref> This proapoptotic activity is conditional and depends on the absence of ligand Dickkopf1.<ref name=":0" /> 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.<ref>{{Cite journal|last1=Ellwanger|first1=Kristina|last2=Saito|first2=Hiroaki|last3=Clément-Lacroix|first3=Philippe|last4=Maltry|first4=Nicole|last5=Niedermeyer|first5=Joachim|last6=Lee|first6=Woon Kyu|last7=Baron|first7=Roland|last8=Rawadi|first8=Georges|last9=Westphal|first9=Heiner|date=2008-08-01|title=Targeted disruption of the Wnt regulator Kremen induces limb defects and high bone density|journal=Molecular and Cellular Biology|volume=28|issue=15|pages=4875–4882|doi=10.1128/MCB.00222-08|issn=1098-5549|pmc=2493355|pmid=18505822}}</ref>
==References== {{reflist}}
==Further reading== {{refbegin | 2}} *{{cite journal |vauthors=Gerhard DS, Wagner L, Feingold EA, etal |title=The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). |journal=Genome Res. |volume=14 |issue= 10B |pages= 2121–7 |year= 2004 |pmid= 15489334 |doi= 10.1101/gr.2596504 | pmc=528928 }} *{{cite journal |vauthors=Brandenberger R, Wei H, Zhang S, etal |title=Transcriptome characterization elucidates signaling networks that control human ES cell growth and differentiation. |journal=Nat. Biotechnol. |volume=22 |issue= 6 |pages= 707–16 |year= 2005 |pmid= 15146197 |doi= 10.1038/nbt971 |s2cid=27764390 }} *{{cite journal |vauthors=Ota T, Suzuki Y, Nishikawa T, etal |title=Complete sequencing and characterization of 21,243 full-length human cDNAs. |journal=Nat. Genet. |volume=36 |issue= 1 |pages= 40–5 |year= 2004 |pmid= 14702039 |doi= 10.1038/ng1285 |doi-access= free }} *{{cite journal |vauthors=Strausberg RL, Feingold EA, Grouse LH, etal |title=Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences. |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=99 |issue= 26 |pages= 16899–903 |year= 2003 |pmid= 12477932 |doi= 10.1073/pnas.242603899 | pmc=139241 |bibcode=2002PNAS...9916899M |doi-access=free }} *{{cite journal |vauthors=Mao B, Wu W, Davidson G, etal |title=Kremen proteins are Dickkopf receptors that regulate Wnt/beta-catenin signalling. |journal=Nature |volume=417 |issue= 6889 |pages= 664–7 |year= 2002 |pmid= 12050670 |doi= 10.1038/nature756 |bibcode=2002Natur.417..664M |s2cid=4418943 }} *{{cite journal |vauthors=Dias Neto E, Correa RG, Verjovski-Almeida S, etal |title=Shotgun sequencing of the human transcriptome with ORF expressed sequence tags. |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=97 |issue= 7 |pages= 3491–6 |year= 2000 |pmid= 10737800 |doi=10.1073/pnas.97.7.3491 | pmc=16267 |bibcode=2000PNAS...97.3491D |doi-access=free }} *{{cite journal |vauthors=Dunham I, Shimizu N, Roe BA, etal |title=The DNA sequence of human chromosome 22. |journal=Nature |volume=402 |issue= 6761 |pages= 489–95 |year= 1999 |pmid= 10591208 |doi= 10.1038/990031 |bibcode=1999Natur.402..489D |doi-access= free }} {{refend}}
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