Stimulation of the phosphorylation of cytoskeletal 350-kDa and 300-kDa proteins by insulin-like growth factor-I, platelet-derived growth factor and phorbol ester in rat 3Y1 cells

Insulin-like growth factor-I (IGF-I) stimulated the phosphorylation of cytoskeletal 350-kDa and 300-kDa proteins which were immunoprecipitated with antibodies against brain high molecular weight microtubule-associated proteins in quiescent rat 3Y1 cells. The data on the effective concentrations of IGF-I and 125I-labeled IGF-I binding indicated that type I IGF receptors mediate this IGF-I effect. Platelet-derived growth factor (PDGF) as well as phorbol ester (TPA) also stimulated the phosphorylation of these proteins. These proteins, whether immunoprecipitated from cells stimulated by insulin, IGF-I, TPA, PDGF, or epidermal growth factor, produced very similar phosphopeptide mapping patterns irrespective of the stimulant. The results suggest the possibility that these growth factors and phorbol esters may activate a common protein kinase which is responsible for the phosphorylation of the 350-kDa and 300-kDa proteins in cells.     

The First Symbiont-Free Genome Sequence of Marine Red Alga,Susabi-nori (Pyropia yezoensis)

Nori, a marine red alga, is one of the most profitable mariculture crops in the world. However, the biological properties of this macroalga are poorly understood at the molecular level. In this study, we determined the draft genome sequence of susabi-nori (Pyropia yezoensis) using next-generation sequencing platforms. For sequencing, thalli of P. yezoensis were washed to remove bacteria attached on the cell surface and enzymatically prepared as purified protoplasts. The assembled contig size of the P. yezoensis nuclear genome was approximately 43 megabases (Mb), which is an order of magnitude smaller than the previously estimated genome size. A total of 10,327 gene models were predicted and about 60% of the genes validated lack introns and the other genes have shorter introns compared to large-genome algae, which is consistent with the compact size of the P. yezoensis genome. A sequence homology search showed that 3,611 genes (35%) are functionally unknown and only 2,069 gene groups are in common with those of the unicellular red alga, Cyanidioschyzon merolae. As color trait determinants of red algae, light-harvesting genes involved in the phycobilisome were predicted from the P. yezoensis nuclear genome. In particular, we found a second homolog of phycobilisome-degradation gene, which is usually chloroplast-encoded, possibly providing a novel target for color fading of susabi-nori in aquaculture. These findings shed light on unexplained features of macroalgal genes and genomes, and suggest that the genome of P. yezoensis is a promising model genome of marine red algae.     

Effect of phospholipase A treatment of low density lipoproteins on the dextran sulfate--lipoprotein interaction

The effect of phospholipase A on the interaction of low density lipoproteins of the S(f) 0-10 class with dextran sulfate was studied in phosphate buffer of pH 7.4, ionic strength 0.1, by chemical, spectrophotometric, and centrifugal methods. When low density lipoproteins that had been treated with phospholipase A were substituted for untreated lipoproteins, the amount of insoluble dextran sulfate-lipoprotein complex formed was greatly reduced. Hydrolysis of over 20% of the lecithin and phosphatidyl ethanolamine constituents of the lipoproteins prevented the formation of insoluble complex. However, even the lipoproteins in which almost all the phosphoglycerides were hydrolyzed produced soluble complex, which was converted to insoluble complex upon addition of magnesium sulfate. It is apparent that the lipoproteins altered extensively by treatment with phospholipase A retain many characteristic properties of native low density lipoproteins. Fatty acids, but not lysolecithin, released by the action of phospholipase A interfered with the formation of insoluble complex; this interference was due to association of the fatty acids with the lipoproteins. With increases in the concentration of the associated fatty acids, the amounts of magnesium ion required for the conversion of soluble complex to insoluble complex increased progressively. Charge interaction is evidently of paramount importance in the formation of sulfated polysaccharide-lipoprotein complexes.     

Effect of Thiolactomycin on Fatty Acid Synthesis in Higher Plants

Thiolactomycin (TLM), an antibiotic from Nocardia sp. No. 2-200,inhibited fatty acid synthesis in Avena leaves, with the concentrationcausing 50% inhibition being 0.38µg/ml. This antibioticis more inhibitory to the elongation of palmitic to oleic acidthan to the de novo synthesis of palmitic acid in both spinachchloroplasts and Avena leaves, in contrast to the effect ofcerulenin which inhibits de novo synthesis but not fatty acidelongation. On the other hand, TLM is less inhibitory to furtherelongation of stearic acid to very long chain fatty acids inpea seeds. The inhibition rate decreased in the order of synthesisof arachidic, behenic and lignoceric acid. (Received December 26, 1986; Accepted April 24, 1987)     

Cross-linking and gel formation of water-soluble lysine polypeptides. An insolubilization model reaction for adhesive proteins.

Insolubilizing studies of water-soluble synthetic polypeptides containing lysine residues were examined using organic aliphatic and aromatic cross-linking agents such as dialdehydes, diacyl chlorides and diactive ester, together with an enzyme tyrosinase, in water and simulated seawater systems. The cross-linking reaction was characterized by the viscosity and turbidity changes. Among the organic cross-linking agents used aliphatic glutaraldehyde and aromatic o-phthalaldehyde were the most effective. When excess organic cross-linking agents were added to the lysine polypeptide systems, the corresponding solid gels were formed. As a whole, the molecular weight of the samples, the amino acid compositions, the cross-linking agent used, the molar ratios between cross-linking agents and functional residues and system pH were found to have roles in the insolubilizing reaction and the gel formation. The cross-linking results obtained were compared with those of the polypeptide-tyrosinase systems, whose deep brownish red colour was decolorized by the addition of L-ascorbic acid.     

Clostridium perfringens--specific lysin.

A mitomycin C induced lysate of Clostridium perfringens strain KZ219 was lytic to 50 strains of C. perfringens of types A-E, and three strains of C. plagarum. The lysin was active against only 2 out of 87 strains of 51 other clostridial species. The optimum pH of the lytic agent was 5.5. The activity was largely inactivated by proteolytic enzymes, and nearly completely inactivated by heating at 60 degrees C for 5 min.     

Phylogenetic position of a whale-fall lancelet (Cephalochordata) inferred from whole mitochondrial genome sequences

Background  

The lancelet Asymmetron inferum (subphylum Cephalochordata) was recently discovered on the ocean floor off the southwest coast of Japan at a depth of 229 m, in an anaerobic and sulfide-rich environment caused by decomposing bodies of the sperm whale Physeter macrocephalus. This deep sulfide-rich habitat of A. inferum is unique among the lancelets. The distinguishing adaptation of this species to such an extraordinary habitat can be considered in a phylogenetic framework. As the first step of reconstruction of the evolutionary processes in this species, we investigated its phylogenetic position based on 11 whole mitochondrial genome sequences including the newly determined ones of the whale-fall lancelet A. inferum and two coral-reef congeners.