Dickkopf-related protein 1 | |||||||
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Identifiers | |||||||
Symbol | DKK1 | ||||||
NCBI gene | 22943 | ||||||
HGNC | 2891 | ||||||
OMIM | 605189 | ||||||
RefSeq | NP_036374 | ||||||
UniProt | O94907 | ||||||
Other data | |||||||
Locus | Chr. 10 q21.1 | ||||||
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Dickkopf-related protein 2 | |||||||
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Identifiers | |||||||
Symbol | DKK2 | ||||||
NCBI gene | 27123 | ||||||
HGNC | 2892 | ||||||
OMIM | 605415 | ||||||
RefSeq | NP_055236 | ||||||
UniProt | Q9UBU2 | ||||||
Other data | |||||||
Locus | Chr. 4 q25 | ||||||
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Dickkopf-related protein 3 | |||||||
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Identifiers | |||||||
Symbol | DKK3 | ||||||
NCBI gene | 27122 | ||||||
HGNC | 2893 | ||||||
OMIM | 605416 | ||||||
RefSeq | NP_037385 | ||||||
UniProt | Q9QUN9 | ||||||
Other data | |||||||
Locus | Chr. 11 p15.3 | ||||||
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Dickkopf-related protein 4 | |||||||
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Identifiers | |||||||
Symbol | DKK4 | ||||||
NCBI gene | 27121 | ||||||
HGNC | 2894 | ||||||
OMIM | 605417 | ||||||
RefSeq | NP_055235 | ||||||
UniProt | Q9UBT3 | ||||||
Other data | |||||||
Locus | Chr. 8 p11.21 | ||||||
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Dickkopf (DKK) is a family of proteins consisting of five members as of 2020. That is, vertebrates usually contain five genes that are members of the family. The most well-studied is Dickkopf-related protein 1 (DKK1). [1] DKK proteins inhibit the Wnt signaling pathway coreceptors LRP5 and LRP6. They bind with high affinity as ligands to KREMEN1 and KREMEN2, which are transmembrane proteins. [2] DKK proteins have important roles in the development of vertebrates. [2]
Dickkopf is a German word meaning "stubborn person", or literally, "thick head". It was coined as the name for these proteins in a 1998 Nature paper by Glinka et al. [3] in reference to the discovery that DKK1 induces head formation in the embryogenesis of Xenopus . [4]
DKK proteins are glycoproteins consisting of 255–350 amino acids. DKK1, DKK2, and DKK4 have similar molecular weights, at 24–29 kDa (kilodaltons). DKK3 is heaviest, at 38 kDa. [2] In addition to having similar weights, DKK1, -2, and -4 have high structural similarity, with two shared cysteine-rich domains. DKK3 differs from -1, -2, and -4 by the presence of a Soggy domain at its N-terminus. [5]
Four DKK proteins and one DKK-like protein occur in humans and other vertebrates, [6] with five proteins in the family in total: [7]
DKK proteins are believed to be involved with several human diseases, including bone cancer and neurodegenerative disease. Evidence also indicates DKK1 and DKK3 are involved in the pathophysiology of the artery, where they could contribute to atherosclerosis. [5]
Xenopus is a genus of highly aquatic frogs native to sub-Saharan Africa. Twenty species are currently described within it. The two best-known species of this genus are Xenopus laevis and Xenopus tropicalis, which are commonly studied as model organisms for developmental biology, cell biology, toxicology, neuroscience and for modelling human disease and birth defects.
The Wnt signaling pathways are a group of signal transduction pathways which begin with proteins that pass signals into a cell through cell surface receptors. The name Wnt is a portmanteau created from the names Wingless and Int-1. Wnt signaling pathways use either nearby cell-cell communication (paracrine) or same-cell communication (autocrine). They are highly evolutionarily conserved in animals, which means they are similar across animal species from fruit flies to humans.
Transcription factor 7-like 2 , also known as TCF7L2 or TCF4, is a protein acting as a transcription factor that, in humans, is encoded by the TCF7L2 gene. The TCF7L2 gene is located on chromosome 10q25.2–q25.3, contains 19 exons. As a member of the TCF family, TCF7L2 can form a bipartite transcription factor and influence several biological pathways, including the Wnt signalling pathway.
Glycogen synthase kinase-3 beta, (GSK-3 beta), is an enzyme that in humans is encoded by the GSK3B gene. In mice, the enzyme is encoded by the Gsk3b gene. Abnormal regulation and expression of GSK-3 beta is associated with an increased susceptibility towards bipolar disorder.
Frizzled-5(Fz-5) is a protein that in humans is encoded by the FZD5 gene.
Frizzled-8(Fz-8) is a protein that in humans is encoded by the FZD8 gene.
Dickkopf-related protein 1 is a protein that in humans is encoded by the DKK1 gene.
Low-density lipoprotein receptor-related protein 6 is a protein that in humans is encoded by the LRP6 gene. LRP6 is a key component of the LRP5/LRP6/Frizzled co-receptor group that is involved in canonical Wnt pathway.
Protein Wnt-3a is a protein that in humans is encoded by the WNT3A gene.
Dickkopf-related protein 3 is a protein in the Dickkopf family that in humans is encoded by the DKK3 gene.
Protein Wnt-7a is a protein that in humans is encoded by the WNT7A gene.
Wnt inhibitory factor 1 is a protein that in humans is encoded by the WIF1 gene. WIF1 is a lipid-binding protein that binds to Wnt proteins and prevents them from triggering signalling.
Protocadherin FAT1 is a protein that in humans is encoded by the FAT1 gene.
Proto-oncogene protein Wnt-3 is a protein that in humans is encoded by the WNT3 gene.
Dickkopf-related protein 2 is a protein in the Dickkopf family that in humans is encoded by the DKK2 gene.
Protein Wnt-11 is a protein that in humans is encoded by the WNT11 gene.
Protein Wnt-9a is a protein that in humans is encoded by the WNT9A gene.
Kremen protein 1 is a protein that in humans is encoded by the KREMEN1 gene. Kremen1 is conserved in chordates including amphioxus and most vertebrate species. The protein is a type I transmembrane receptor of ligands Dickkopf1, Dickkopf2, Dickkopf3, Dickkopf4, EpCAM and Rspondin1.
Wingless-type MMTV integration site family, member 2, also known as WNT2, is a human gene.
In molecular biology miR-203 is a short non-coding RNA molecule. MicroRNAs function to regulate the expression levels of other genes by several mechanisms, such as translational repression and Argonaute-catalyzed messenger RNA cleavage. miR-203 has been identified as a skin-specific microRNA, and it forms an expression gradient that defines the boundary between proliferative epidermal basal progenitors and terminally differentiating suprabasal cells. It has also been found upregulated in psoriasis and differentially expressed in some types of cancer.