A Small-Molecule Inhibitor of T. gondii Motility Induces the Posttranslational Modification of Myosin Light Chain-1 and Inhibits Myosin Motor Activity

Toxoplasma gondii is an obligate intracellular parasite that enters cells by a process of active penetration. Host cell penetration and parasite motility are driven by a myosin motor complex consisting of four known proteins: TgMyoA, an unconventional Class XIV myosin; TgMLC1, a myosin light chain; and two membrane-associated proteins, TgGAP45 and TgGAP50. Little is known about how the activity of the myosin motor complex is regulated. Here, we show that treatment of parasites with a recently identified small-molecule inhibitor of invasion and motility results in a rapid and irreversible change in the electrophoretic mobility of TgMLC1. While the precise nature of the TgMLC1 modification has not yet been established, it was mapped to the peptide Val46-Arg59. To determine if the TgMLC1 modification is responsible for the motility defect observed in parasites after compound treatment, the activity of myosin motor complexes from control and compound-treated parasites was compared in an in vitro motility assay. TgMyoA motor complexes containing the modified TgMLC1 showed significantly decreased motor activity compared to control complexes. This change in motor activity likely accounts for the motility defects seen in the parasites after compound treatment and provides the first evidence, in any species, that the mechanical activity of Class XIV myosins can be modulated by posttranslational modifications to their associated light chains

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

The sequence and analysis of duplication rich human chromosome 16

We report here the 78,884,754 base pairs of finished human chromosome 16 sequence, representing over 99.9 percent of its euchromatin. Manual annotation revealed 880 protein coding genes confirmed by 1,637 aligned transcripts, 19 tRNA genes, 341 pseudogenes and 3 RNA pseudogenes. These genes include metallothionein, cadherin and iroquois gene families, as well as the disease genes for polycystic kidney disease and acute myelomonocytic leukemia. Several large-scale structural polymorphisms spanning hundreds of kilobasepairs were identified and result in gene content differences across humans. One of the unique features of chromosome 16 is its high level of segmental duplication, ranked among the highest of the human autosomes. While the segmental duplications are enriched in the relatively gene poor pericentromere of the p-arm, some are involved in recent gene duplication and conversion events which are likely to have had an impact on the evolution of primates and human disease susceptibility

The sequence and analysis of duplication-rich human chromosome 16

Human chromosome 16 features one of the highest levels of segmentally duplicated sequence among the human autosomes. We report here the 78,884,754 base pairs of finished chromosome 16 sequence, representing over 99.9% of its euchromatin. Manual annotation revealed 880 protein-coding genes confirmed by 1,670 aligned transcripts, 19 transfer RNA genes, 341 pseudogenes and three RNA pseudogenes. These genes include metallothionein, cadherin and iroquois gene families, as well as the disease genes for polycystic kidney disease and acute myelomonocytic leukaemia. Several large-scale structural polymorphisms spanning hundreds of kilobase pairs were identified and result in gene content differences among humans. Whereas the segmental duplications of chromosome 16 are enriched in the relatively gene-poor pericentromere of the p arm, some are involved in recent gene duplication and conversion events that are likely to have had an impact on the evolution of primates and human disease susceptibility.Joel Martin, Cliff Han, Laurie A. Gordon, Astrid Terry, Shyam Prabhakar, Xinwei She, Gary Xie, Uffe Hellsten, Yee Man Chan, Michael Altherr, Olivier Couronne, Andrea Aerts, Eva Bajorek, Stacey Black, Heather Blumer, Elbert Branscomb, Nancy C. Brown, William J. Bruno, Judith M. Buckingham, David F. Callen, Connie S. Campbell, Mary L. Campbell, Evelyn W. Campbell, Chenier Caoile, Jean F. Challacombe, Leslie A. Chasteen, Olga Chertkov, Han C. Chi, Mari Christensen, Lynn M. Clark, Judith D. Cohn, Mirian Denys, John C. Detter, Mark Dickson, Mira Dimitrijevic-Bussod, Julio Escobar, Joseph J. Fawcett, Dave Flowers, Dea Fotopulos, Tijana Glavina, Maria Gomez, Eidelyn Gonzales, David Goodstein, Lynne A. Goodwin, Deborah L. Grady, Igor Grigoriev, Matthew Groza, Nancy Hammon, Trevor Hawkins, Lauren Haydu, Carl E. Hildebrand, Wayne Huang, Sanjay Israni, Jamie Jett, Phillip B. Jewett, Kristen Kadner, Heather Kimball, Arthur Kobayashi, Marie-Claude Krawczyk, Tina Leyba, Jonathan L. Longmire, Frederick Lopez, Yunian Lou, Steve Lowry, Thom Ludeman, Chitra F. Manohar, Graham A. Mark, Kimberly L. McMurray, Linda J. Meincke, Jenna Morgan, Robert K. Moyzis, Mark O. Mundt, A. Christine Munk, Richard D. Nandkeshwar, Sam Pitluck, Martin Pollard Paul Predki, Beverly Parson-Quintana, Lucia Ramirez, Sam Rash, James Retterer, Darryl O. Ricke, Donna L. Robinson, Alex Rodriguez, Asaf Salamov, Elizabeth H. Saunders, Duncan Scott, Timothy Shough, Raymond L. Stallings, Malinda Stalvey, Robert D. Sutherland, Roxanne Tapia, Judith G. Tesmer, Nina Thayer, Linda S. Thompson, Hope Tice, David C. Torney, Mary Tran-Gyamfi, Ming Tsai, Levy E. Ulanovsky, Anna Ustaszewska, Nu Vo, P. Scott White, Albert L. Williams, Patricia L. Wills, Jung-Rung Wu, Kevin Wu, Joan Yang, Pieter DeJong, David Bruce, Norman A. Doggett, Larry Deaven, Jeremy Schmutz, Jane Grimwood, Paul Richardson, Daniel S. Rokhsar, Evan E. Eichler, Paul Gilna, Susan M. Lucas, Richard M. Myers, Edward M. Rubin and Len A. Pennacchi