In the budding yeast Saccharomyces cerevisiae, the Cdc3p, Cdc10p, Cdc11p, Cdc12p, and Sep7p/Shs1p septins assemble early in the cell cycle in a ring that marks the future cytokinetic site. The septins appear to be major structural components of a set of filaments at the mother-bud neck and function as a scaffold for recruiting proteins involved in cytokinesis and other processes. We isolated a novel gene, BNI5, as a dosage suppressor of the cdc12-6 growth defect. Overexpression of BNI5 also suppressed the growth defects of cdc10-1, cdc11-6, and sep7⌬ strains. Loss of BNI5 resulted in a cytokinesis defect, as evidenced by the formation of connected cells with shared cytoplasms, and deletion of BNI5 in a cdc3-6, cdc10-1, cdc11-6, cdc12-6, or sep7⌬ mutant strain resulted in enhanced defects in septin localization and cytokinesis. Bni5p localizes to the mother-bud neck in a septin-dependent manner shortly after bud emergence and disappears from the neck approximately 2 to 3 min before spindle disassembly. Two-hybrid, in vitro binding, and protein-localization studies suggest that Bni5p interacts with the N-terminal domain of Cdc11p, which also appears to be sufficient for the localization of Cdc11p, its interaction with other septins, and other critical aspects of its function. Our data suggest that the Bni5p-septin interaction is important for septin ring stability and function, which is in turn critical for normal cytokinesis.Cytokinesis in animal cells involves an actomyosin-based contractile ring, which forms late in the cell cycle and constricts the plasma membrane, resulting in the division of one cell into two cells. In the budding yeast Saccharomyces cerevisiae, the cleavage plane is specified early in the cell cycle, and cytokinesis involves the concerted action of actomyosin ring contraction and septum formation (5, 37, 55). Despite some differences in the morphological features and timing of certain cytokinetic events between yeast and animal cells, many of the components involved are conserved (18). In addition to the conserved involvement of the actomyosin contractile ring, it is now widely appreciated that the septins also play a critical role in cytokinesis in both yeast and animal cells.Septins are a family of proteins that were identified first in yeast and subsequently in various other fungi and animals (for review, see references 20, 32, and 39). Septin family members possess at least 26% amino acid sequence identity. All of the known septins possess an N-terminal P-loop and other sequences conserved in the GTPase superfamily of nucleotidebinding proteins (8). In addition, at or near their C termini, most septins possess a predicted coiled-coil domain (for review, see reference 39) that may be important in proteinprotein interactions.In yeast, the Cdc3p, Cdc10p, Cdc11p, Cdc12p, and Sep7p (or Shs1p) septins all localize to the presumptive bud site before bud emergence and remain at the mother-bud neck until after cytokinesis (11,21,28,33,45; M. S. Longtine, unpublished observations). Recent studies...

Macrolepiota procera, one of edible mushrooms belongs to Agaricaceae of Basidiomycota, has a good taste and good medicinal value. As a preliminary study for the development of artificial cultivation method of edible mushroom, cultural characteristics of M. procera was investigated on various culture media under different environmental conditions. Mycelial growth was compared on culture media composed of various carbon and nitrogen sources, and C/N ratios. The optimal conditions for the mycelial growth were 30℃ and pH 7. M. procera showed the rapid mycelial growth in the PDA media. The optimal carbon and nitrogen sources were maltose and glycine, respectively. The optimum C/N ratio was about 10 : 1 in case that 1% glucose was supplemented to the basal media as carbon source.

Cystoderma amianthinum, one of edible fungi belongs to Agaricaceae of Basidiomycota, has a good taste and flavor. This study was carried out to obtain the basic informations for the optimum mycelial growth of C. amianthinum. The optimal conditions for the mycelial growth were 25℃ and pH 5 in potato dextrose agar (PDA). C. amianthinum showed the favorable growth in the PDA and yeast malt extract agar (YMA). The favorable carbon and nitrogen sources promoting mycelial growth were fructose and histidine, respectively. The optimum C/N ratio was about 30 : 1 in case that 1% glucose was supplemented to the basal medium as a carbon source.

The polo-box domain of the budding yeast polo kinase Cdc5p plays an essential role for targeting the catalytic activity of Cdc5p to spindle pole bodies (SPBs) and cytokinetic neck-filaments. Here, we report the isolation of Bbp1p as a polo-box interacting protein by a yeast two-hybrid screen. Bbp1p localizes to the periphery of the central plaque of the SPB and plays an important role in SPB duplication. Similarly, Cdc5p localized to the cytoplasmic periphery of the SPB. In vitro binding studies showed that Cdc5p interacted with the N-terminal domain of Bbp1p (Bbp1pDeltaC), but apparently not with Mps2p, a component shown to form a stable complex with Bbp1p. In addition, Bbp1p, but likely not Mps2p, was required for proper localization of Cdc5p to the SPB. The C-terminal coiled-coil domain of Bbp1p (Bbp1p(243-385)), which is crucial for both the homodimerization and the SPB localization, could target the localization-defective Cdc5pDeltaC to the SPB and induce the release of Cdc14p from the nucleolus. Consistent with this observation, expression of CDC5DeltaC-BBP1(243-385) under CDC5 promoter control partially complemented the cdc5Delta defect. These data suggest that Bbp1pDeltaC interacts with the polo-box domain of Cdc5p, and this interaction is critical for the subcellular localization and mitotic functions of Cdc5p.