IDENTIFICATION OF A 48-KDA PRENYLATED PROTEIN THAT ASSOCIATES WITH MICROTUBULES AS 2',3'-CYCLIC NUCLEOTIDE 3'-PHOSPHODIESTERASE IN FRTL-5 CELLS

In an effort to study the nature of tubulin attachment to membranes, w e have previously observed that after blocking prenylation in FRTL-5 t hyroid cells, the microtubules become disconnected from the plasma mem brane region [Bifulco M. et al. (1983) J. Cell. Physiol. 155, 340-348] . In this study we show that several [H-3]mevalonate labeled proteins in FRTL-5 cells associate with membrane and cytoskeleton and, among th ese, we describe the presence of a 48-kDa prenylated protein, identifi ed by immunoprecipitation as 2',3'-cyclic nucleotide 3'-phosphodiester ase (CNP), that associates with microtubules, This latter association persists through several polymerization/depolymerization cycles, where as other prenylated proteins are lost, It is suggested that CNP can be a novel microtubule-associated protein (MAP) and a promising candidat e as a membrane anchor for microtubules. (C) 1997 Federation of Europe an Biochemical Societies.