Anticonvulsant activity of farnesylacetone epoxide—a novel marine natural product

Summary A marine natural product, farnesylacetone epoxide, which is chemically related to juvenile hormone, has anticonvulsant properties at nonsedative doses in mice.     

Esterases in the hearts,lungs and livers of human foetuses before mid-term

Zusammenfassung Verschiedene Fraktionen von Esterasen in embryonalem Gewebe und enzymatische Reifungsprozesse während der Ontogenese werden beschrieben.

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I wish to thank ProfessorG. A. G. Mitchell, Dr. S. R. Choudhury andMr. A. M. Lundy for their help and advice.     

Male tarsal sex-comb teeth pattern in theDrosophila bipectinata complex

Summary Species within theD. bipectinata species complex pose problems experimentally because of their morphological similarity. By measuring the number of teeth in each row of the male tarsal sex-comb, an unknown specimen can be allocated to a hybrid or parental group by means of a discriminant function. This paper describes which rows of the sex-comb are the best discriminators for particular comparisons.Acknowledgments. We thank L. Anderson and P. Rowbury for technical and research assistance, Dr I. Bock for providing fly stocks and for his continued interest and helpful discussions, and the Australian Research Grants Scheme for financial assistance.     

Direct evidence that oncogenic tyrosine kinases and cyclic AMP-dependent protein kinase have homologous ATP-binding sites

p60src, the transforming protein of Rous sarcoma virus (RSV), is a protein kinase that has a strict specificity for tyrosine. The phosphorylation of cellular proteins by p60src (ref. 4) results in transformation. Recently, Barker and Dayhoff discovered that residues 259-485 of p60src have 22% sequence identity with residues 33-258 of the catalytic subunit of cyclic AMP-dependent protein kinase, an enzyme that has a specificity for serine. Because it was necessary to introduce eight gaps to align the two proteins, the question remained as to whether this apparent homology reflected a common evolutionary origin. We demonstrate here that the ATP analogue p-fluorosulphonylbenzoyl 5'-adenosine (FSBA) inactivates the tyrosine protein kinase activity of p60src by reacting with lysine 295. When aligned for maximum sequence identity, lysine 295 of p60src and the lysine in the catalytic subunit which also reacts specifically with FSBA are superimposed precisely. This functional homology is strong evidence that the protein kinases, irrespective of amino acid substrate specificity, comprise a single divergent gene family.     

Interferon receptors and their role in interferon action

Summary Interferon (IFN)_proteins interact with cells through specific cell surface receptors, some of which have been purified and cloned. The alpha-IFNs and beta-IFN bind to a common receptor (type I), whereas gamma-IFN binds to a separate receptor (type II). Both types of high-affinity receptors have been demonstrated on a variety of different kinds of cells but in relatively low numbers (10²–10⁴/cell). The relationship between IFN binding to receptors and the ways in which IFNs may affect cellular physiology and gene expression is discussed.