A model of the molecular phylogeny of the LNX family. A LNX1/2-like protein is likely to have arisen through genomic rearrangements in a very early metazoan that combined a RING domain with four PDZ domains. The LNX PDZ domains are derived from PDZ domains encoded by an ancestral gene that also gave rise to the four carboxy-terminal PDZ domains of MUPP1 (PDZ 10-13). LNX3/4-like proteins resulted from the loss of two PDZ domains and the acquisition or evolution of a novel carboxy-terminal region including what we define here as a LNX3 homology domain. Gene duplications of both of these invertebrate LNX genes gave rise to the LNX1/LNX2/LNX2b and LNX3/LNX4/LNX5 subfamilies in vertebrates. A loss of exons encoding the RING and one PDZ domain occurred to give rise to LNX5.
Flynn et al. BMC Evolutionary Biology 2011 11:235 doi:10.1186/1471-2148-11-235