Willin is a novel member of the Four-point-one Ezrin Radixin Moesin
(FERM) protein superfamily, containing an N-terminal FERM domain most like the
Ezrin-Radixin-Moesin (ERM) family but also the closely related protein Merlin.
Willin was initially discovered as a yeast two-hybrid binding partner of
neurofascin155, and this interaction has now been confirmed by both co-localisation
studies and the use of two different biochemical methods. Like neurofascin155,
Willin also localises to detergent resistant membranes, and like the ERM family, it is
able to bind to phospholipids. The expression of Willin appears to be toxic as the
production of cell-lines stably expressing Willin proved to be not possible and this
appears to be because it induces apoptosis in cultured cells. This is a proliferation
control function consistent with the suggestion that Willin is the human homologue of the Drosophila tumour suppressor ‘Expanded’. Three antibodies to Willin were also characterised and a novel splice variant, Willin2, subcloned into a GFP-tagged
plasmid for comparison with the original form.