69structure and function and offers a platform to advance both biological and medically
useful knowledge concerning this important RNA-binding protein.
2.7.6 The Bic-C RNA-Binding Element
The results described above were exploited to define a Bic-C RNA binding site, the
first defined for any Bic-C ortholog (Zhang et al. 2014 ). Bic-C proteins contain
multiple heteronucleoprotein K homology (KH) domains that are known to function
as sequence-specific RNA-binding modules (Gamberi and Lasko 2012 ; Hollingworth
et al. 2012 ; Teplova et al. 2011 ; Nakel et al. 2010 ; Valverde et al. 2008 ). The
Fig. 2.5 Spatially regulated translation of the Cripto-1 mRNA by the Bic-C repressor. (a) Bic-C
represses the Cripto-1 mRNA in vegetal cells of Xenopus embryos. The Cripto-1 mRNA is trans-
lated in animal cells but repressed in vegetal cells. Vegetal cell repression requires Bic-C binding
to its recognition element, a sequence within the Cripto-1 mRNA’s 3′UTR (Heasman 2006a;
Houston 2013 ; Zhang et al. 2013 , 2014 ). (b) The 32nt Bic-C binding site and its predicted stem-
loop structure identified from the translational control element (TCE) of the Cripto-1 mRNA
3 ′UTR (Heasman 2006a; Zhang et al. 2014 )
2 Controlling the Messenger...