Inspired by the high specific capacitances found using ultrathin films or nanoparticles of manganese oxides (MnO(x)), we have electrodeposited MnO(x) nanoparticles onto sheets of carbon nanotubes (CNT sheets). The resulting composites have high specific capacitances (C(sp) ≤ 1250 F/g), high charge/discharge rate capabilities, and excellent cyclic stability. Both the C(sp) and rate capabilities are controlled by the average size of the MnO(x) nanoparticles on the CNTs. They are independent of the number of layers of CNT sheets used to form an electrode. The high-performance composites result from a synergistic combination of large surface area and good electron-transport capabilities of the MnO(x) nanoparticles with the good conductivity of the CNT sheets. Such composites can be used as electrodes for lithium batteries and supercapacitors.

Members of the polo subfamily of protein kinases have emerged as important regulators in diverse aspects of the cell cycle and cell proliferation. A large body of evidence suggests that a highly conserved polo-box domain (PBD) present in the C-terminal non-catalytic region of polo kinases play a pivotal role in the function of these enzymes. Recent advances in our comprehension of the mechanisms underlying mammalian polo-like kinase 1 (Plk1)-dependent protein-protein interactions revealed that the PBD serves as an essential molecular mediator that brings the kinase domain of Plk1 in proximity with its substrates mainly through phospho-dependent interactions with its target proteins. In this review, current understanding of the structure and functions of PBD, mode of PBDdependent interactions and substrate phosphorylation, and other phospho-independent functions of PBD are discussed.

Outer Dense Fiber 2 (ODF2) was initially identified as a major component of the sperm tail cytoskeleton, and was later suggested to be localized to somatic centrosomes and required for the formation of primary cilia. Here, we showed that a splice variant of hODF2 called hCenexin1, but not hODF2 itself, efficiently localizes to somatic centrosomes via an isoform-specific C-terminal extension and recruits Plk1 through a Cdc2-dependent phospho-S796 motif within the extension. This interaction and Plk1 activity were important for proper recruitment of pericentrin and γ-tubulin, and, ultimately, for formation of normal bipolar spindles. Earlier in the cell cycle, hCenexin1, but again not hODF2, also contributed to centrosomal recruitment of ninein and primary cilia formation independent of Plk1 interaction. These findings provide a unique example of how a splice-generated C-terminal extension of a sperm tail-associating protein mediates unanticipated centrosomal events at distinct stages of the somatic cell cycle.