Monounsaturated Fatty Acid Modificationof Wnt Protein: Its Role in Wnt Secretion

Takada R, Developmental Cell (2006)

Ciani L, Nature (2005)

Coudreuse D, Development (2007)

Wntless/Evi, a seven-pass membrane protein, plays an essential role in Wnt secretion.

Banziger C, Cell (2006) and Bartscherer K, Cell (2006)

The retromer complex, participates in the long-range transport of Wnt protein

Coudreuse D, Development (2007)

Willert K, Nature (2003)

- Wnt is a family of cysteine-rich secreted glycoproteins.

Mason JO, Mol Biol Cell (1992)

- Wnt proteins are lipid-modified (palmitoylated).

- The Porcupine (Porc) may be involved in secretion or ER transport and has some homology to a family of O-acyl transferases and may be involved in lipid modification of Wnt proteins.

Porc

Linder ME, Journal of Cell Science (2004)

- Wg secretion is inhibited in the absence of Porc, whereas Wnt3a (C77A) is secreted normally.

- According to mass spectrometry analysis of Wnt-3a, there remains the possibility of additional acylation sites.

Ser209 Is Required for Acylation of Wnt-3a.

Wnt-3a Is Modified with a Monounsaturated Fatty Acid at Ser209

Ser209 Is Essential for Secretion of Wnt-3a

Porcupine Is Required for the Acylation and Secretion of Wnt-3a

Wnt-3a with Defective Acylation Is Not Transferred from the ER

Ser209 Is Required for the Function and Appropriate Localization of Wnt-3a in Xenopus Embryos