Table 1.

Wnt antagonist family molecules

Name(s)Mechanism of actionWnt antagonist activityWnt agonist activity/inhibition of antagonist activity
sFRP1 (FRP, SARP2, FrzA) SFRP1Binds Wnt and FzYes (Finch et al., 1997; Xu et al., 1998; Uren et al., 2000)Agonist at low concentrations (Uren et al., 2000)
sFRP2 (SARP1) SFRP2Binds WntYes (Ladher et al., 2000)Inhibits sFRP1 (Yoshino et al., 2001)
sFRP3 (FrzB, Fritz) FRZBBinds WntYes (Leyns et al., 1997; Wang et al., 1997a; Wang et al., 1997b; Lin et al., 1997; Mayr et al., 1997)
sFRP4 (FrzB-2) SFRP4Binds Wnt?
sFRP5 (SARP3) SFRP5Binds Wnt?
Sizzled*Binds Wnt (?)Yes (Salic et al., 1997) No (Bradley et al., 2000; Collavin and Kirschner, 2003)
Sizzled2*Binds Wnt (?)No (Bradley et al., 2000)
Crescent*Binds WntYes (Pera and De Robertis, 2000)
WIF-1Binds WntYes (Hsieh et al., 1999)
Cerberus*Binds WntYes (Piccolo et al., 1999)
Coco*Binds Wnt (?)Yes (Bell et al., 2003)
Dkk-1 (DKK1)Binds LRP5/6Yes (Glinka et al., 1998; Krupnik et al., 1999; Fedi et al., 1999; Wu et al., 2000; Brott and Sokol, 2002)Inhibits Dkk-2 (Wu et al., 2000)
Dkk-2 (DKK2)Binds LRP5/6No (in Xenopus embryos, Krupnik et al., 1999; Wu et al., 2000) Yes (in Xenopus embryos, Brott and Sokol, 2002) Yes (in cell lines, Wu et al., 2000; Li et al., 2002)Agonist (Wu et al., 2000) Agonist with LRP6 (Li et al., 2002; Brott and Sokol, 2002)
Dkk-3 (REIC) (DKK3)No (Krupnik et al., 1999; Mao and Niehrs, 2003)
Dkk-4 (DKK4)Binds LRP5/6 (?)Yes (Krupnik et al., 1999; Mao and Niehrs, 2003)
Soggy (DKKL2)No (Krupnik et al., 1999)
Approved gene symbols are underlined.
  • * To date, mammalian genes for Sizzled, Sizzled2 and Crescent have not been identified. The mammalian gene related to Cerberus (mCer1) does not encode a Wnt antagonist, and the antagonist activity of mammalian Coco has not been tested.