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2004

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University of Massachusetts Medical School

Molecular Genetics

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Articles 1 - 9 of 9

Full-Text Articles in Life Sciences

Chromosomal Duplications And Cointegrates Generated By The Bacteriophage Lamdba Red System In Escherichia Coli K-12, Anthony R. Poteete, Anita C. Fenton, Ashwini Nadkarni Dec 2004

Chromosomal Duplications And Cointegrates Generated By The Bacteriophage Lamdba Red System In Escherichia Coli K-12, Anthony R. Poteete, Anita C. Fenton, Ashwini Nadkarni

Open Access Articles

BACKGROUND: An Escherichia coli strain in which RecBCD has been genetically replaced by the bacteriophage lambda Red system engages in efficient recombination between its chromosome and linear double-stranded DNA species sharing sequences with the chromosome. Previous studies of this experimental system have focused on a gene replacement-type event, in which a 3.5 kbp dsDNA consisting of the cat gene and flanking lac operon sequences recombines with the E. coli chromosome to generate a chloramphenicol-resistant Lac- recombinant. The dsDNA was delivered into the cell as part of the chromosome of a non-replicating lambda vector, from which it was released by ...


The Histone Fold Domain Of Cse4 Is Sufficient For Cen Targeting And Propagation Of Active Centromeres In Budding Yeast, Lisa Morey, Kelly Barnes, Yinhuai Chen, Molly Fitzgerald-Hayes, Richard E. Baker Dec 2004

The Histone Fold Domain Of Cse4 Is Sufficient For Cen Targeting And Propagation Of Active Centromeres In Budding Yeast, Lisa Morey, Kelly Barnes, Yinhuai Chen, Molly Fitzgerald-Hayes, Richard E. Baker

Open Access Articles

Centromere-specific H3-like proteins (CenH3s) are conserved across the eukaryotic kingdom and are required for packaging centromere DNA into a specialized chromatin structure required for kinetochore assembly. Cse4 is the CenH3 protein of the budding yeast Saccharomyces cerevisiae. Like all CenH3 proteins, Cse4 consists of a conserved histone fold domain (HFD) and a divergent N terminus (NT). The Cse4 NT contains an essential domain designated END (for essential N-terminal domain); deletion of END is lethal. To investigate the role of the Cse4 NT in centromere targeting, a series of deletion alleles (cse4DeltaNT) were analyzed. No part of the Cse4 NT was ...


Translational Regulation Of Gene Expression, Stephanie Kervestin, Nadia Amrani Dec 2004

Translational Regulation Of Gene Expression, Stephanie Kervestin, Nadia Amrani

Open Access Articles

A report on the Cold Spring Harbor Laboratory meeting 'Translational Control', Cold Spring Harbor, USA, 7-12 September 2004.


Judging A Virus By Its Cover, Eva Szomolanyi-Tsuda, Raymond M. Welsh Oct 2004

Judging A Virus By Its Cover, Eva Szomolanyi-Tsuda, Raymond M. Welsh

Open Access Articles

The production of protective neutralizing antibodies occurs quickly in some viral infections but very slowly in others. In a new study, surface glycoproteins (the targets of neutralization) of 2 different viruses were genetically switched. Analysis of the neutralizing antibody response to each of the 2 parent and recombinant viruses in infected mice revealed that the speed of neutralizing antibody induction was intrinsically dependent on the surface glycoprotein and not the rest of the virus.


Bone Marrow Microenvironmental Changes Underlie Reduced Rag-Mediated Recombination And B Cell Generation In Aged Mice, Joseph E. Labrie, Alex P. Sah, David M. Allman, Michael P. Cancro, Rachel M. Gerstein Aug 2004

Bone Marrow Microenvironmental Changes Underlie Reduced Rag-Mediated Recombination And B Cell Generation In Aged Mice, Joseph E. Labrie, Alex P. Sah, David M. Allman, Michael P. Cancro, Rachel M. Gerstein

Open Access Articles

During aging, adaptive immunity is severely compromised, due in part to decreased production of B lymphocytes and loss of immunoglobulin (Ig) diversity. However, the molecular mechanisms that underlie age-associated diminished B cell production remain unclear. Using in vivo labeling, we find that this reduction in marrow pre-B cells reflects increased attrition during passage from the pro-B to pre-B cell pool. Analyses of reciprocal bone marrow chimeras reveal that the magnitude and production rates of pre-B cells are controlled primarily by microenvironmental factors, rather than intrinsic events. To understand changes in pro-B cells that could diminish production of pre-B cells, we ...


A Novel Phosphatidylinositol(3,4,5)P3 Pathway In Fission Yeast, Prasenjit Mitra, Yingjie Zhang, Lucia E. Rameh, Mariya P. Ivshina, Dannel Mccollum, John J. Nunnari, Gregory M. Hendricks, Monica L. Kerr, Seth J. Field, Lewis C. Cantley, Alonzo H. Ross Jul 2004

A Novel Phosphatidylinositol(3,4,5)P3 Pathway In Fission Yeast, Prasenjit Mitra, Yingjie Zhang, Lucia E. Rameh, Mariya P. Ivshina, Dannel Mccollum, John J. Nunnari, Gregory M. Hendricks, Monica L. Kerr, Seth J. Field, Lewis C. Cantley, Alonzo H. Ross

Open Access Articles

The mammalian tumor suppressor, phosphatase and tensin homologue deleted on chromosome 10 (PTEN), inhibits cell growth and survival by dephosphorylating phosphatidylinositol-(3,4,5)-trisphosphate (PI[3,4,5]P3). We have found a homologue of PTEN in the fission yeast, Schizosaccharomyces pombe (ptn1). This was an unexpected finding because yeast (S. pombe and Saccharomyces cerevisiae) lack the class I phosphoinositide 3-kinases that generate PI(3,4,5)P3 in higher eukaryotes. Indeed, PI(3,4,5)P3 has not been detected in yeast. Surprisingly, upon deletion of ptn1 in S. pombe, PI(3,4,5)P3 became detectable at ...


Mapping Of Catalytically Important Residues In The Rat L-Histidine Decarboxylase Enzyme Using Bioinformatic And Site-Directed Mutagenesis Approaches, John V. Fleming, Francisca Sanchez-Jimenez, Aurelio A. Moya-Garcia, Michael R. Langlois, Timothy C. Wang Feb 2004

Mapping Of Catalytically Important Residues In The Rat L-Histidine Decarboxylase Enzyme Using Bioinformatic And Site-Directed Mutagenesis Approaches, John V. Fleming, Francisca Sanchez-Jimenez, Aurelio A. Moya-Garcia, Michael R. Langlois, Timothy C. Wang

Open Access Articles

HDC (L-histidine decarboxylase), the enzyme responsible for the catalytic production of histamine from L-histidine, belongs to an evolutionarily conserved family of vitamin B6-dependent enzymes known as the group II decarboxylases. Yet despite the obvious importance of histamine, mammalian HDC enzymes remain poorly characterized at both the biochemical and structural levels. By comparison with the recently described crystal structure of the homologous enzyme L-DOPA decarboxylase, we have been able to identify a number of conserved domains and motifs that are important also for HDC catalysis. This includes residues that were proposed to mediate events within the active site, and HDC proteins ...


Developmental Separation Of V(D)J Recombinase Expression And Initiation Of Igh Recombination In B Lineage Progenitors In Vivo, Lisa A. Borghesi, Rachel M. Gerstein Feb 2004

Developmental Separation Of V(D)J Recombinase Expression And Initiation Of Igh Recombination In B Lineage Progenitors In Vivo, Lisa A. Borghesi, Rachel M. Gerstein

Open Access Articles

In B lineage progenitors, V(D)J recombination occurs only during distinct stages of development and is restricted to immunoglobulin loci. This process is thought to be controlled by both regulated expression of the V(D)J recombinase and by limited accessibility of target loci to the recombinase complex. However, it is unknown whether these two processes occur concomitantly in developing B lineage progenitors or whether these events are temporally distinct and, therefore, potentially independently regulated. To distinguish between these possibilities, we developed a transgenic V(D)J recombination substrate that is not governed by the same chromatin remodeling constraints ...


B Lineage-Specific Regulation Of V(D)J Recombinase Activity Is Established In Common Lymphoid Progenitors, Lisa A. Borghesi, Lih-Yun Hsu, Juli P. Miller, Michael Anderson, Leonard A. Herzenberg, Leonore A. Herzenberg, Mark S. Schlissel, David M. Allman, Rachel M. Gerstein Feb 2004

B Lineage-Specific Regulation Of V(D)J Recombinase Activity Is Established In Common Lymphoid Progenitors, Lisa A. Borghesi, Lih-Yun Hsu, Juli P. Miller, Michael Anderson, Leonard A. Herzenberg, Leonore A. Herzenberg, Mark S. Schlissel, David M. Allman, Rachel M. Gerstein

Open Access Articles

Expression of V(D)J recombinase activity in developing lymphocytes is absolutely required for initiation of V(D)J recombination at antigen receptor loci. However, little is known about when during hematopoietic development the V(D)J recombinase is first active, nor is it known what elements activate the recombinase in multipotent hematopoietic progenitors. Using mice that express a fluorescent transgenic V(D)J recombination reporter, we show that the V(D)J recombinase is active as early as common lymphoid progenitors (CLPs) but not in the upstream progenitors that retain myeloid lineage potential. Evidence of this recombinase activity is ...