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Full-Text Articles in Medicine and Health Sciences

A Schiff Base Connectivity Switch In Sensory Rhodopsin Signaling, Oleg A Sineshchekov, Jun Sasaki, Brian J Phillips, John L Spudich Oct 2008

A Schiff Base Connectivity Switch In Sensory Rhodopsin Signaling, Oleg A Sineshchekov, Jun Sasaki, Brian J Phillips, John L Spudich

Journal Articles

Sensory rhodopsin I (SRI) in Halobacterium salinarum acts as a receptor for single-quantum attractant and two-quantum repellent phototaxis, transmitting light stimuli via its bound transducer HtrI. Signal-inverting mutations in the SRI-HtrI complex reverse the single-quantum response from attractant to repellent. Fast intramolecular charge movements reported here reveal that the unphotolyzed SRI-HtrI complex exists in two conformational states, which differ by their connection of the retinylidene Schiff base in the SRI photoactive site to inner or outer half-channels. In single-quantum photochemical reactions, the conformer with the Schiff base connected to the cytoplasmic (CP) half-channel generates an attractant signal, whereas the conformer …


The Cradle Of The Deltaf508 Mutation, Danish Saleheen, Philippe M Frossard Oct 2008

The Cradle Of The Deltaf508 Mutation, Danish Saleheen, Philippe M Frossard

Department of Biological & Biomedical Sciences

Cystic fibrosis (CF) is the most common autosomal recessive disorder caused due to mutation/s in the CFTR gene. The most common mutation in CFTR worldwide is deltaF508 and cystic fibrosis genetic analysis consortium revealed that this mutation is responsible for approximately 66% of all CF chromosomes in the world. Studies looking at the DNA polymorphic haplotypes created by CF linked markers suggest that deltaF508 has a single origin as this mutation has been found associated exclusively with one marker haplotype. Despite a high prevalence of this mutation in CF patients in northern parts of Europe, findings suggest that this mutation …


The Cytoplasmic Tail Of The Rabies Virus G Protein Is An Essential Domain Controlling Death/Survival In Human Neuronal Cells, Christophe Prehaud, Mireille Lafage, Gene S. Tan, Françoise Mégret, Pauline Ménager, Matthias Schnell, Henri Buc, Monique Lafon Sep 2008

The Cytoplasmic Tail Of The Rabies Virus G Protein Is An Essential Domain Controlling Death/Survival In Human Neuronal Cells, Christophe Prehaud, Mireille Lafage, Gene S. Tan, Françoise Mégret, Pauline Ménager, Matthias Schnell, Henri Buc, Monique Lafon

Department of Microbiology and Immunology Faculty Papers

Poster presentation.


Missense Mutation In Exon 2 Of Slc36a1 Responsible For Champagne Dilution In Horses, Deborah Cook, Samantha Brooks, Rebecca Bellone, Ernest Bailey Sep 2008

Missense Mutation In Exon 2 Of Slc36a1 Responsible For Champagne Dilution In Horses, Deborah Cook, Samantha Brooks, Rebecca Bellone, Ernest Bailey

Veterinary Science Faculty Publications

Champagne coat color in horses is controlled by a single, autosomal-dominant gene (CH). The phenotype produced by this gene is valued by many horse breeders, but can be difficult to distinguish from the effect produced by the Cream coat color dilution gene (CR). Three sires and their families segregating for CH were tested by genome scanning with microsatellite markers. The CH gene was mapped within a 6 cM region on horse chromosome 14 (LOD = 11.74 for theta = 0.00). Four candidate genes were identified within the region, namely SPARC [Secreted protein, acidic, cysteine-rich (osteonectin)], SLC36A1 (Solute Carrier 36 family …


Staphylococcus Aureus Pbp4 Is Essential For Β-Lactam Resistance In Community-Acquired Methicillin-Resistant Strains, G Memmi, S R. Filipe, M G. Pinho, Z Fu, Ambrose Cheung Aug 2008

Staphylococcus Aureus Pbp4 Is Essential For Β-Lactam Resistance In Community-Acquired Methicillin-Resistant Strains, G Memmi, S R. Filipe, M G. Pinho, Z Fu, Ambrose Cheung

Dartmouth Scholarship

Recent cases of infections caused by community-acquired methicillin-resistant Staphylococcus aureus (MRSA) (CA-MRSA) strains in healthy individuals have raised concerns worldwide. CA-MRSA strains differ from hospital-acquired MRSAs by virtue of their genomic background and increased virulence in animal models.


Ponticulin Plays A Role In The Positional Stabilization Of Pseudopods, D. C. Shutt, D. Wessels, K. Wagenknecht, A. Chandrasekhar, Anne L. Hitt, Elizabeth J. Luna, D. R. Soll Mar 2008

Ponticulin Plays A Role In The Positional Stabilization Of Pseudopods, D. C. Shutt, D. Wessels, K. Wagenknecht, A. Chandrasekhar, Anne L. Hitt, Elizabeth J. Luna, D. R. Soll

Elizabeth J. Luna

Ponticulin is a 17-kD glycoprotein that represents a major high affinity link between the plasma membrane and the cortical actin network of Dictyostelium. To assess the role of ponticulin in pseudopod extension and retraction, the motile behavior of two independently generated mutants lacking ponticulin was analyzed using computer-assisted two- and three-dimensional motion analysis systems. More than half of the lateral pseudopods formed off the substratum by ponticulin-minus cells slipped relative to the substratum during extension and retraction. In contrast, all pseudopods formed off the substratum by wild-type cells were positionally fixed in relation to the substratum. Ponticulin-minus cells also formed …


Gating Charge Immobilization In Kv4.2 Channels: The Basis Of Closed-State Inactivation., Kevin Dougherty, Jose A De Santiago-Castillo, Manuel Covarrubias Mar 2008

Gating Charge Immobilization In Kv4.2 Channels: The Basis Of Closed-State Inactivation., Kevin Dougherty, Jose A De Santiago-Castillo, Manuel Covarrubias

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Kv4 channels mediate the somatodendritic A-type K+ current (I(SA)) in neurons. The availability of functional Kv4 channels is dynamically regulated by the membrane potential such that subthreshold depolarizations render Kv4 channels unavailable. The underlying process involves inactivation from closed states along the main activation pathway. Although classical inactivation mechanisms such as N- and P/C-type inactivation have been excluded, a clear understanding of closed-state inactivation in Kv4 channels has remained elusive. This is in part due to the lack of crucial information about the interactions between gating charge (Q) movement, activation, and inactivation. To overcome this limitation, we engineered a charybdotoxin …


Abeta42 Mutants With Different Aggregation Profiles Induce Distinct Pathologies In Drosophila., Koichi Iijima, Hsueh-Cheng Chiang, Stephen A Hearn, Inessa Hakker, Anthony Gatt, Christopher Shenton, Linda Granger, Amy Leung, Kanae Iijima-Ando, Yi Zhong Feb 2008

Abeta42 Mutants With Different Aggregation Profiles Induce Distinct Pathologies In Drosophila., Koichi Iijima, Hsueh-Cheng Chiang, Stephen A Hearn, Inessa Hakker, Anthony Gatt, Christopher Shenton, Linda Granger, Amy Leung, Kanae Iijima-Ando, Yi Zhong

Department of Biochemistry and Molecular Biology Faculty Papers

Aggregation of the amyloid-beta-42 (Abeta42) peptide in the brain parenchyma is a pathological hallmark of Alzheimer's disease (AD), and the prevention of Abeta aggregation has been proposed as a therapeutic intervention in AD. However, recent reports indicate that Abeta can form several different prefibrillar and fibrillar aggregates and that each aggregate may confer different pathogenic effects, suggesting that manipulation of Abeta42 aggregation may not only quantitatively but also qualitatively modify brain pathology. Here, we compare the pathogenicity of human Abeta42 mutants with differing tendencies to aggregate. We examined the aggregation-prone, EOFAD-related Arctic mutation (Abeta42Arc) and an artificial mutation (Abeta42art) that …