Dynamics of peroxisome assembly and function

Recent studies in human cells and in the yeast Yarrowia lipolytica have sho wn that peroxisomes consist of numerous structurally distinct subcompartmen ts that differ in their import competency for various proteins and are rela ted through a time-ordered conversion of one subcompartment to another. Our studies have implicated the fusion of small peroxisomal precursors as an e arly event in the multistep assembly of peroxisomes operating in Y. lipolyt ica. Newly discovered unexpected roles for peroxisomes in specific developm ental programs have expanded the remarkable plasticity of peroxisomal funct ions. Here, we highlight recent discoveries on the highly dynamic nature of peroxisome assembly and function and suggest questions for future research in these areas.