Discrimination in partnership: compartment-specific interactions of Hox proteins

Abstract

A relatively small number of regulatory proteins perform multiple functions to orchestrate the develo pment of an animal from a zygote. Many regulatory proteins are tra nscription factors that affect the expression of dow nstream genes. These factors interact with other proteins in the nucleus to regulate expression of their target genes. The main effect of loss -of-function mutations in genes encoding major regulators of develop ment is lethality at the earliest stage where the regulatory molecule is r equired. Many, very important roles of regulatory factors have been inferred from these lethal phenotypes. Ho wever, the early lethality means that u nderstanding the later roles, if any, of such genes becomes difficult. In addition, loss -offunction studies alone do not usually provide insights into the identity and role of interacting proteins critical for the final output of the regulatory si gnal.