Vertebrate hedgehog signaling depends on the passage and/or localization of many of the pathway components through the primary cilium (reviewed in Goetz and Anderson, 2010). Although GLI and SUFU proteins are not concentrated in the cilium in the absence of Hh signaling, processing and/or degradation of the transcription factors requires transit through the cilium and basal levels of these proteins can be detected there (Wen et al, 2010; Tukachinsky et al, 2010; Kim et al, 2006; Liu et al, 2005; Haycraft et 2005). Consistent with this, members of both the IFT-B and IFT-A complex, as well as components of the ciliary basal body and the kinesin-2 and dynein motor proteins have been identified as regulators of Hh signaling (Huangfu et al, 2003; Tran et al, 2008; Liu et al, 2005; Houde et al, 2006; Huangfu et al, 2005; May et al, 2005; Cortellino et al, 2009; Vierkotten et al, 2007; Ferrante et al, 2006; Weatherbee et al, 2009; Liem et al, 2012; Qin et al 2011). KIF7, a microtubule-associated kinesin-type motor that negatively regulates the length of axonemal microtubules, is also required for correct localization of GLI:SUFU (He et al, 2014). Finally, a number of PCP pathway effectors have recently been shown to be required for ciliogenesis, and mutations in these genes disrupt GLI processing (Zeng et al, 2010; Gray et al, 2009; Heydeck et al, 2009; Park et al, 2006).

Vertebrate hedgehog signaling depends on the passage and/or localization of many of the pathway components through the primary cilium (reviewed in Goetz and Anderson, 2010). Although GLI and SUFU proteins are not concentrated in the cilium in the absence of Hh signaling, processing and/or degradation of the transcription factors requires transit through the cilium and basal levels of these proteins can be detected there (Wen et al, 2010; Tukachinsky et al, 2010; Kim et al, 2006; Liu et al, 2005; Haycraft et 2005). Consistent with this, members of both the IFT-B and IFT-A complex, as well as components of the ciliary basal body and the kinesin-2 and dynein motor proteins have been identified as regulators of Hh signaling (Huangfu et al, 2003; Tran et al, 2008; Liu et al, 2005; Houde et al, 2006; Huangfu et al, 2005; May et al, 2005; Cortellino et al, 2009; Vierkotten et al, 2007; Ferrante et al, 2006; Weatherbee et al, 2009; Liem et al, 2012; Qin et al 2011). KIF7, a microtubule-associated kinesin-type motor that negatively regulates the length of axonemal microtubules, is also required for correct localization of GLI:SUFU (He et al, 2014). Finally, a number of PCP pathway effectors have recently been shown to be required for ciliogenesis, and mutations in these genes disrupt GLI processing (Zeng et al, 2010; Gray et al, 2009; Heydeck et al, 2009; Park et al, 2006).