|CD344||FZD4 (frizzled homolog 4), Frizzled-4, Fz-4, hFz-4, FzE4|
|Molecule Type||Antigen Expression||Molecular Weight|
Min / Max
|Non-lineage Restricted Molecule|
Type 3 glycoprotein, 7 span
|60 / 60|
|CD344 is largely expressed in kidney, lung, brain and liver. There is moderate expression in pancreas, and spleen with lowl expression in placenta, prostate, testis and colon. Expression is also by fetal neuronal progentior cells and neuronal intestinal cells.|
|MOLECULAR FAMILY NAME: Belongs to the G-protein coupled receptor, Frizzled family.|
CD344 is a multi-pass type-3 501 aa glycoprotein. It contains an 186 aa extracellular N-terminus domain which contains a cysteine-rich ligand binding domain with 2 cysteine residues in the second and third extracellular loops and 2 N-linked glycosylation sites, 7 transmembrane-spanning domains and 39 aa cytoplasmic C-terminal domain that contains a Lys-Thr-X-X-X-Trp motif. This motif is the binding site for PDZ-domain containing proteins and is essential for activation of the Wnt/β-catenin pathway. Most frizzled receptors are coupled to the β-catenin canonical signaling pathway, which leads to the activation of dishevelled proteins, inhibition of GSK-3 kinase, nuclear accumulation of β-catenin and activation of Wnt target genes. A second pathway involving PKC and calcium fluxes has been seen for some family members, but it is not yet clear if it represents a distinct pathway or if it can be integrated in the canonical pathways, as PKC seem to be required for Wnt-mediated inactivation of GSK-3 kinase. Both pathways seem to involved interactions with G-proteins. This protein may play a role as a positive regulator of Wnt integration site signaling pathway. Studies suggest that CD344 may form heterodimers.
POST-TRANSCRIPTIONAL MODIFICATION: No information.
CD344 has 2 N-linked glycosylation sites.
|LIGANDS AND MOLECULES ASSOCIATED WITH CD344|
The CD344 domain is involved with Wnt proteins and norrin (Norrie disease pseudoglioma homolog).
CD344 is a marker for neuronal stem cells. CD344 is essential for the regulation of tissue and cell polarity, embryonic development, regulation of proliferation and many other processes in developing and adult organisms. CD344 is a receptor for Wnt proteins and norrie and participates in the activation of the Wnt/β-catenin pathway (canonical Wnt signaling) and is involved in coupling to members of the G proteins. These interactions with G-proteins may be involved in transduction and intercellular transmission of information during tissue morphogenesis and/or in differentiated tissues.
PROTEINS AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD344: No information.
SUBSTRATES: No information.
ENZYMES WHICH MODIFY CD344: No information.
Database accession numbers
Revised June 25, 2008