CLONING OF HUMAN ERYTHROID DEMATIN REVEALS ANOTHER MEMBER OF THE VILLIN FAMILY

Dematin is an actin-bundling protein originally identified in the huma n erythroid membrane skeleton. Its actin-bundling activity is abolishe d upon phosphorylation by the cAMP-dependent protein kinase and is res tored after dephosphorylation. Here we report the complete primary str ucture of human erythroid dematin, whose sequence includes a homologue of the ''headpiece'' sequence found at the C terminus of villin. This headpiece is essential for villin function in inducing microvillar de velopment and actin redistribution. The widespread expression of demat in transcripts in human tissues suggests that dematin and its homologu es may substitute for villin in villin-negative tissues to regulate ac tin reorganization by a phosphorylation-regulated mechanism.