Peroxisomal Biogenesis Factor 11 Gamma (PEX11g)

Pex11g expression in mouse liver was not induced by ciprofibrate, and no change in Pex11g expression was detected in cells lacking either Pex11a or Pex11b. Overexpression of PEX11G did not increase peroxisome abundance, but induced tubulation, enlargement, and clustering of peroxisomes. Phylogenic analysis determined that PEX11G represents a subfamily of PEX11 proteins distinct from the branch that includes PEX11A and PEX11B. Pex11g expression was below the level of detection in mouse fibroblasts. Transfection of epitope-tagged PEX11G into a human fibroblast cell line revealed colocalization with PEX14 , a peroxisome marker protein. Analysis of PEX11G domains detected in permeabilized cells suggested that PEX11G is a peroxisomal membrane protein with both the N and C termini exposed to the cytoplasm.