- The Saccharomyces cerevisiae spindle pole body (SPB) component Nbp1p is required for SPB membrane insertion and interacts with the integral membrane proteins Ndc1p and Mps2p. Araki, Y., Lau, C.K., Maekawa, H., Jaspersen, S.L., Giddings, T.H., Schiebel, E., Winey, M. Mol. Biol. Cell (2006)