Articles by D. Ellen K. Tarr in JoVE
Creating and Applying a Reference to Facilitate the Discussion and Classification of Proteins in a Diverse Group D. Ellen K. Tarr1 1Department of Microbiology and Immunology, Arizona College of Osteopathic Medicine, Midwestern University The goal of this protocol is to develop a reference for divergent proteins in a group that lacks coherent criteria for nomenclature and classification. This reference will facilitate analyses and discussion of the group as a whole and can be used in addition to established names.
Other articles by D. Ellen K. Tarr on PubMed
TIR-NBS-LRR Genes Are Rare in Monocots: Evidence from Diverse Monocot Orders BMC Research Notes. Sep, 2009 | Pubmed ID: 19785756 Plant resistance (R) gene products recognize pathogen effector molecules. Many R genes code for proteins containing nucleotide binding site (NBS) and C-terminal leucine-rich repeat (LRR) domains. NBS-LRR proteins can be divided into two groups, TIR-NBS-LRR and non-TIR-NBS-LRR, based on the structure of the N-terminal domain. Although both classes are clearly present in gymnosperms and eudicots, only non-TIR sequences have been found consistently in monocots. Since most studies in monocots have been limited to agriculturally important grasses, it is difficult to draw conclusions. The purpose of our study was to look for evidence of these sequences in additional monocot orders.
Distribution and Characteristics of ABFs, Cecropins, Nemapores, and Lysozymes in Nematodes Developmental and Comparative Immunology. Mar, 2012 | Pubmed ID: 21978453 Several groups of antimicrobial effector molecules have been identified in nematodes, but most studies have been limited to Caenorhabditis elegans and, to a lesser extent, Ascaris suum. Although these two species are not closely related, they are not representative of overall nematode diversity. This study utilized available sequence information to investigate whether four groups of antimicrobial effectors (defensin-like antibacterial factors [ABFs], cecropins, saposin domain-containing proteins, and lysozymes) are components of an archetypal nematode immune system or more narrowly restricted. Saposin domain-containing proteins (caenopores in C. elegans) and lysozymes were widely distributed and found in most taxa, but likely have digestive as well as defensive functions. ABFs were widely distributed in fewer taxa, suggesting selective loss in some lineages. In contrast, cecropins were identified in only three related species, suggesting acquisition of this effector molecule in their common ancestor.
Establishing a Reference Array for the CS-αβ Superfamily of Defensive Peptides BMC Research Notes. Nov, 2016 | Pubmed ID: 27863510 "Invertebrate defensins" belong to the cysteine-stabilized alpha-beta (CS-αβ), also known as the scorpion toxin-like, superfamily. Some other peptides belonging to this superfamily of defensive peptides are indistinguishable from "defensins," but have been assigned other names, making it unclear what, if any, criteria must be met to qualify as an "invertebrate defensin." In addition, there are other groups of defensins in invertebrates and vertebrates that are considered to be evolutionarily unrelated to those in the CS-αβ superfamily. This complicates analyses and discussions of this peptide group. This paper investigates the criteria for classifying a peptide as an invertebrate defensin, suggests a reference cysteine array that may be helpful in discussing peptides in this superfamily, and proposes that the superfamily (rather than the name "defensin") is the appropriate context for studying the evolution of invertebrate defensins with the CS-αβ fold.