Electrophoretic analysis of basal body (centriole) proteins

Purified basal bodies isolated from the chicken oviduct were analyzed by using several different electrophoretic techniques. For comparison, oviduct cilia proteins were also analyzed. Prominent among the basal body proteins were the tubulin subunits (representing approximately 20% of the protein) and a low molecular weight protein (approximately 17,400 daltons). In addition, major bands were present with molecular weights of approximately 180,000 and approximately 90,000. Electrophoretically purified basal body tubulin subunits had isoelectric points of 5.45 (alpha subunit) and 5.1 (beta subunit). In addition, these isoelectric focus gels contained at least four other proteins that had higher isoelectric points, which indicates that tubulin purified by one-dimensional electrophoresis contains other proteins. On the basis of several different electrophoretic techniques, it was found that basal body tubulin differed from cilia tubulin even though they both had similar isoelectric focusing points. Whereas basal bodies did not contain any proteins that corresponded to the cilia dynein ATPase, five different sets of proteins were common to both cilia and basal bodies. Basal bodies did not contain significant amounts of actin, myosin, or desmin.