Where are the dolphins?

Interest in extraterrestrial life has tended to focus on a search for extrasolar planets similar to the Earth. But what of forms of intelligent life that are very different from those found on Earth? Some features of life will not be peculiar to our planet, and alien life will resemble ours in such universals. But if intelligent, non-humanoid aliens exist, where might they be? Would they wish to visit Earth and would we know if they did?     

Molecular cloning and expression of the major protein kinase C substrate of platelets

In platelets, agonists that stimulate phosphoinositide turnover cause the rapid phosphorylation of a protein of apparent relative molecular mass (Mr) 40-47,000, called P47, by protein kinase C (PKC). Diverse identities have been ascribed to P47 including lipocortin, inositol 1,4,5-trisphosphate 5-phosphomonoesterase, pyruvate dehydrogenase alpha subunit and an actin regulatory protein. We have isolated human P47 clones by immunological screening of a lambda gt11 complementary DNA library from HL-60 cells, a human promyelocytic leukaemia cell line. P47 recombinants thus identified hybridized to a 3.0 kilobase (kb) messenger RNA in mature white blood cell lines; the same mRNA was induced in HL-60 cells during differentiation. A 1,050 base pair (bp) open reading frame that could encode a protein of Mr40,087 was confirmed by comparison with peptide sequences from platelet P47, and by expression of the putative recombinant P47 in E. coli and in vitro. The P47 sequence appears to have been conserved throughout vertebrate evolution, and is not similar to any other known sequence including human lipocortin and the alpha subunit of pyruvate dehydrogenase. The P47 protein contains a potential Ca2+-binding 'EF-hand' structure and a region that strongly resembles known PKC phosphorylation sites.     

Electron microscopy of frozen-hydrated biological material

The electron microscopy of frozen-hydrated specimens has the potential to allow biological material to be examined in conditions very similar to the native state, and so has excited considerable interest. Although not all of the problems associated with the method have been solved, the technique has already provided important insights into macromolecular structure and assembly and promises to be a powerful tool for investigating the structure of cellular components and their interactions.     

The cytoplasmic fatty-acid-binding proteins: thirty years and counting

The interest in fatty-acid-binding proteins has produced about 1000 research papers since their discovery nearly 30 years ago. This review provides an entry to the mammalian and nonmammalian literature through a compendium of categorized review articles (nearly 60). Publications that have not yet been reviewed, particularly of function and modes of action, are presented and discussed in light of earlier reports. This large protein family may be integral in the relationship between lipid and carbohydrate metabolism.