Rare occurrence of the tetratype tetrads in Saccharomycodes ludwigii.

Genetic data suggesting the absence of crossover in Saccharomycodes ludwigii have been described. Tetrad data obtained from 888 asci from 60 pairs of genes with 22 genetic markers showed the absence of tetratype asci, except for 5 asci in which a single pair of alleles showed tetratype segregation to the other genetic markers in each ascus. Spore arrays in the linear asci showed that the + - + - and + - - + (or - + + -) asci occurred at almost equal frequencies. The two coherent spores at each end of an ascus were always marked with different alleles of a gene.     

Securiosides A and B, novel acylated triterpene bisdesmosides with selective cytotoxic activity against M-CSF-stimulated macrophages

We report the discovery of securiosides A (1) and B (2), novel acylated triterpene bisdesmosides, isolated from the roots of Securidaca inappendiculata. Securiosides A and B showed potent selective cytotoxic activity against M-CSF-stimulated macrophages and were suggested to have potential as new agents for the treatment of inflammatory diseases such as RA and atherosclerosis.     

The yeast Tor signaling pathway is involved in G2/M transition via polo-kinase

The target of rapamycin (Tor) protein plays central roles in cell growth. Rapamycin inhibits cell growth and promotes cell cycle arrest at G1 (G0). However, little is known about whether Tor is involved in other stages of the cell division cycle. Here we report that the rapamycin-sensitive Tor complex 1 (TORC1) is involved in G2/M transition in S. cerevisiae. Strains carrying a temperature-sensitive allele of KOG1 (kog1-105) encoding an essential component of TORC1, as well as yeast cell treated with rapamycin show mitotic delay with prolonged G2. Overexpression of Cdc5, the yeast polo-like kinase, rescues the growth defect of kog1-105, and in turn, Cdc5 activity is attenuated in kog1-105 cells. The TORC1-Type2A phosphatase pathway mediates nucleocytoplasmic transport of Cdc5, which is prerequisite for its proper localization and function. The C-terminal polo-box domain of Cdc5 has an inhibitory role in nuclear translocation. Taken together, our results indicate a novel function of Tor in the regulation of cell cycle and proliferation.     

cis‐Regulatory analysis for later phase of anterior neuroectoderm‐specific foxQ2 expression in sea urchin embryos

The specification of anterior neuroectoderm is controlled by a highly conserved molecular mechanism in bilaterians. A forkhead family gene, foxQ2, is known to be one of the pivotal regulators, which is zygotically expressed in this region during embryogenesis of a broad range of bilaterians. However, what controls the expression of this essential factor has remained unclear to date. To reveal the regulatory mechanism of foxQ2, we performed cis‐regulatory analysis of two foxQ2 genes, foxQ2a and foxQ2b, in a sea urchin Hemicentrotus pulcherrimus. In sea urchin embryos, foxQ2 is initially expressed in the entire animal hemisphere and subsequently shows narrower expression restricted to the anterior pole region. In this study, as a first step to understand the foxQ2 regulation, we focused on the later restricted expression and analyzed the upstream cis‐regulatory sequences of foxQ2a and foxQ2b by using the constructs fused to short half‐life green fluorescent protein. Based on deletion and mutation analyses of both foxQ2, we identified each of the five regulatory sequences, which were 4–9 bp long. Neither of the regulatory sequences contains any motifs for ectopic activation or spatial repression, suggesting that later mRNA localization is regulated in situ. We also suggest that the three amino acid loop extension‐class homeobox gene Meis is involved in the maintenance of foxQ2b, the expression of which is dominant during embryogenesis.     

Release of cytotoxin by macrophages on treatment with human placenta lectin

Human lectin purified from placenta induced release of cytotoxin from a murine macrophage cell line and human peritoneal monocytes. This activity was not due to contamination of the lectin preparation with lipopolysaccharide.     

Immunological detection of adulteration of ground meats by meats of other origins

Specific and sensitive assays for immunoglobulin G in pork, chicken, and beef were developed using polyester cloths coated with respective anti-immunoglobulin G antibodies. The captured immunoglobulin G proteins were detected by their reactions with the respective IgG antibody horseradish peroxidase conjugates and a chromogenic peroxidase substrate. This sensitive assay takes only 30 minutes and can detect the adulteration of ground meats.     

Topochemical analysis of morphiceptin and dermorphin bioactivities.

To elucidate the topochemical requirements for bioactivities of morphiceptin (Tyr-Pro-Phe-Pro-NH2) and dermorphin (Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2), we have designed and synthesized two diastereomers Tyr-(L and D)-(NMe)Ala-Phe-D-Pro-NH2. Both the analogs display high activities in the guinea pig ileum assay. The only difference in the composition of these two diastereomers arises from the chirality at residue 2. The high mu-receptor activities are attributed to structures where the Tyr1-L-(NMe)Ala2 amide bond assumes a cis configuration while the Tyr1-D-(NMe)Ala2 amide bond assumes a trans configuration. Accessible space studied for the second residues of these molecules confirms the fact that the L-(NMe)Ala2 analog belongs to the morphiceptin family of opioids while the D-(NMe)Ala2 analog belongs to the dermorphin class of opioids. The similarity in the spacial array of the analogs explains their high mu-receptor activities and indicates that they are likely recognized at the same opioid receptor.     

1H NMR studies of deuterated ribonuclease HI selectively labeled with protonated amino acids

Summary Two-dimensional (2D)¹H NMR experiments using deuterium labeling have been carried out to investigate the solution structure of ribonuclease HI (RNase HI) fromEscherichia coli (E. coli), which consists of 155 amino acids. To simplify the¹H NMR spectra, two fully deuterated enzymes bearing several prototed amino acids were prepared from an RNase HI overproducing strain ofE. coli grown in an almost fully deuterated medium. One enzyme was selectively labeled by protonated His, He. Val. and Leu. The other was labeled by only protonated His and Ile. The 2D¹H NMR spectra of these deuterated R Nase H1 proteins, selectively labeled with protonated amino acids, were much more simple than those of the normally protonated enzyme. The simplified spectra allowed unambiguous assignments of the resonance peaks and connectivities in COSY and NOESY for the side-chain protons. The spin-lattice relaxation times of the side-chain protons of the buried His residue of the deuterated enzyme became remarkably longer than that of the protonated enzyme. In contrast, the relaxation times of the side-chain protons of exposed His residues remained essentially unchanged.