Siah-1 mediates a novel beta-catenin degradation pathway linking p53 to the adenomatous polyposis coli protein.

The adenomatous polyposis coli (APC) tumor-suppressor protein, together with Axin and GSK3beta, forms a Wnt-regulated signaling complex that mediates phosphorylation-dependent degradation of beta-catenin by the proteasome. Siah-1, the human homolog of Drosophila seven in absentia, is a p53-inducible mediator of cell cycle arrest, tumor suppression, and apoptosis. We have now found that Siah-1 interacts with the carboxyl terminus of APC and promotes degradation of beta-catenin in mammalian cells.

Complete base sequence for the mitochondrial large subunit ribosomal RNA of the gypsy moth Lymantria dispar (L.).

A 1355 bp sequence (accession number L32141) isolated from a gypsy moth (Lymantria dispar) cDNA library showed 68-74% sequence identity to mitochondrial large subunit ribosomal RNA (mt IrRNA) sequences of Locusta migratoria, Apis mellifera, Aedes albopictus, Anopheles gambiae and two Drosophila species. A comparison of the primary sequences of the mt IrRNAs from the above insects in four orders and from Esherichia coli demonstrated regions of conservation which presumably correspond to regions of functional and/or structural homology. A secondary structure for the gypsy moth mt IrRNA sequence was derived based on the proposed secondary structures of Drosophila yakuba and Aedes albopictus mt IrRNAs (Gutell & Fox, Nucleic Acid Res 16 (Suppl.

Evolution of regulatory genes and patterns: relationships to evolutionary rates and to metabolic functions.

In an effort to understand the forces shaping evolution of regulatory genes and patterns, we have compared data on interspecific differences in enzyme expression patterns among the rapidly evolving Hawaiian picture-winged Drosophila to similar data on the more conservative virilis species group. Divergence of regulatory patterns is significantly more common in the former group, but cause and effect are difficult to discern. Random fixation of regulatory variants in small populations and/or during speciation may be somewhat more likely than divergence driven by selection.