The LRR and RING domain protein LRSAM1 is an E3 ligase crucial for ubiquitin-dependent autophagy of intracellular Salmonella Typhimurium.

Several species of pathogenic bacteria replicate within an intracellular vacuolar niche. Bacteria that escape into the cytosol are captured by the autophagic pathway and targeted for lysosomal degradation, representing a defense against bacterial exploitation of the host cytosol. Autophagic capture of Salmonella Typhimurium occurs predominantly via generation of a polyubiquitin signal around cytosolic bacteria, binding of adaptor proteins, and recruitment of autophagic machinery.

O-GlcNAc protein modification in plants: Evolution and function.

The role in plants of posttranslational modification of proteins with O-linked N-acetylglucosamine and the evolution and function of O-GlcNAc transferases responsible for this modification are reviewed. Phylogenetic analysis of eukaryotic O-GlcNAc transferases (OGTs) leads us to propose that plants have two distinct OGTs, SEC- and SPY-like, that originated in prokaryotes. Animals and some fungi have a SEC-like enzyme while plants have both.

Molecular analysis of a UDP-GlcNAc:polypeptide alpha-N-acetylglucosaminyltransferase implicated in the initiation of mucin-type O-glycosylation in Trypanosoma cruzi.

Trypanosoma cruzi, the causative agent of Chagas disease, is surrounded by a mucin coat that plays important functions in parasite survival/invasion and is extensively O-glycosylated by Golgi and cell surface glycosyltransferases. The addition of the first sugar, alpha-N-acetylglucosamine (GlcNAc) linked to Threonine (Thr), is catalyzed by a polypeptide alpha-GlcNAc-transferase (pp-alphaGlcNAcT) which is unstable to purification. Here, a comparison of the genomes of T.

The evolution of seminal ribonuclease: pseudogene reactivation or multiple gene inactivation events?

Two approaches, one novel, are applied to analyze the divergent evolution of ruminant seminal ribonucleases (RNases), paralogs of the well-known pancreatic RNases of mammals. Here, the goal was to identify periods of divergence of seminal RNase under functional constraints, periods of divergence as a pseudogene, and periods of divergence driven by positive selection pressures. The classical approach involves the analysis of nonsynonymous to synonymous replacements ratios (omega) for the branches of the seminal RNase evolutionary tree.

Molecular paleoscience: systems biology from the past.

Experimental paleomolecular biology, paleobiochemistry, and paleogenetics are closely related emerging fields that infer the sequences of ancient genes and proteins from now-extinct organisms, and then resurrect them for study in the laboratory. The goal of paleogenetics is to use information from natural history to solve the conundrum of modern genomics: How can we understand deeply the function of biomolecular structures uncovered and described by modern chemical biology? Reviewed here are the first 20 cases where biomolecular resurrections have been achieved. These show how paleogenetics can lead to an understanding of the function of biomolecules, analyze changing function, and put meaning to genomic sequences, all in ways that are not possible with traditional molecular biological studies.