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Cellular and Molecular Physiology

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2013

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Articles 1 - 18 of 18

Full-Text Articles in Physiology

Molecular Evolution Of Protein-Rna Mimicry As A Mechanism For Translational Control, Assaf Katz, Lindsey Solden, S. Betty Zou, William Wiley Navarre, Michael Ibba Dec 2013

Molecular Evolution Of Protein-Rna Mimicry As A Mechanism For Translational Control, Assaf Katz, Lindsey Solden, S. Betty Zou, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is a conserved ribosome-binding protein that structurally mimics tRNA to enable the synthesis of peptides containing motifs that otherwise would induce translational stalling, including polyproline. In many bacteria, EF-P function requires post-translational modification with (R)-β-lysine by the lysyl-tRNA synthetase paralog PoxA. To investigate how recognition of EF-P by PoxA evolved from tRNA recognition by aminoacyl-tRNA synthetases, we compared the roles of EF-P/PoxA polar contacts with analogous interactions in a closely related tRNA/synthetase complex. PoxA was found to recognize EF-P solely via identity elements in the acceptor loop, the domain of the protein that interacts with the …


Acclimatization Of The Tropical Reef Coral Acropora Millepora To Hyperthermal Stress, Anthony John Bellantuono Sep 2013

Acclimatization Of The Tropical Reef Coral Acropora Millepora To Hyperthermal Stress, Anthony John Bellantuono

FIU Electronic Theses and Dissertations

The demise of reef-building corals potentially lies on the horizon, given ongoing climate change amid other anthropogenic environmental stressors. If corals cannot acclimatize or adapt to changing conditions, dramatic declines in the extent and health of the living reefs are expected within the next half century. The primary and proximal global threat to corals is climate change. Reef-building corals are dependent upon a nutritional symbiosis with photosynthetic dinoflagellates belonging to the group Symbiodinium. The symbiosis between the cnidarian host and algal partner is a stress-sensitive relationship; temperatures just 1°C above normal thermal maxima can result in the breakdown of …


Aspirin And Low-Molecular Weight Heparin Combination Therapy Effectively Prevents Recurrent Miscarriage In Hyperhomocysteinemic Women., Pratip Chakraborty, Sayani Banerjee, Piyali Saha, Shyam Sundar Nandi, Sunita Sharma, Sourendra K. Goswami, Baidyanath Chakravarty, Syed N. Kabir Sep 2013

Aspirin And Low-Molecular Weight Heparin Combination Therapy Effectively Prevents Recurrent Miscarriage In Hyperhomocysteinemic Women., Pratip Chakraborty, Sayani Banerjee, Piyali Saha, Shyam Sundar Nandi, Sunita Sharma, Sourendra K. Goswami, Baidyanath Chakravarty, Syed N. Kabir

Journal Articles: Cellular & Integrative Physiology

The management of recurrent pregnancy loss (RPL) still remains a great challenge, and women with polycystic ovarian syndrome (PCOS) are at a greater risk for spontaneous abortion. Treatment with low-molecular-weight heparin (LMWH) has become an accepted treatment option for women with RPL; however, the subgroup of women, who are likely to respond to LMWH, has not been precisely identified. The present study evaluated the efficacy of LMWH with reference to PCOS and associated metabolic phenotypes including hyperhomocysteinemia (HHcy), insulin resistance (IR) and obesity. This prospective observational study was conducted at Institute of Reproductive Medicine, Kolkata, India. A total of 967 …


Dirigent Domain-Containing Protein Is Part Of The Machinery Required For Formation Of The Lignin-Based Casparian Strip In The Root, Prashant S. Hosmani, Takehiro Kamiya, John Danku, Sadaf Naseer, Niko Geldner, Mary Lou Guerinot, David Salt Aug 2013

Dirigent Domain-Containing Protein Is Part Of The Machinery Required For Formation Of The Lignin-Based Casparian Strip In The Root, Prashant S. Hosmani, Takehiro Kamiya, John Danku, Sadaf Naseer, Niko Geldner, Mary Lou Guerinot, David Salt

Dartmouth Scholarship

The endodermis acts as a "second skin" in plant roots by providing the cellular control necessary for the selective entry of water and solutes into the vascular system. To enable such control, Casparian strips span the cell wall of adjacent endodermal cells to form a tight junction that blocks extracellular diffusion across the endodermis. This junction is composed of lignin that is polymerized by oxidative coupling of monolignols through the action of a NADPH oxidase and peroxidases. Casparian strip domain proteins (CASPs) correctly position this biosynthetic machinery by forming a protein scaffold in the plasma membrane at the site where …


Direction Of Aminoacylated Transfer Rnas Into Antibiotic Synthesis And Peptidoglycan-Mediated Antibiotic Resistance, Jennifer Shepherd, Michael Ibba Jul 2013

Direction Of Aminoacylated Transfer Rnas Into Antibiotic Synthesis And Peptidoglycan-Mediated Antibiotic Resistance, Jennifer Shepherd, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Prokaryotic aminoacylated‐transfer RNAs often need to be efficiently segregated between translation and other cellular biosynthetic pathways. Many clinically relevant bacteria, including Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa direct some aminoacylated‐tRNA species into peptidoglycan biosynthesis and/or membrane phospholipid modification. Subsequent indirect peptidoglycan cross‐linkage or change in membrane permeability is often a prerequisite for high‐level antibiotic resistance. In Streptomycetes, aminoacylated‐tRNA species are used for antibiotic synthesis as well as antibiotic resistance. The direction of coding aminoacylated‐tRNA molecules away from translation and into antibiotic resistance and synthesis pathways are discussed in this review.


Lipid Ii-Independent Trans Editing Of Mischarged Trnas By The Penicillin Resistance Factor Murm, Jennifer Shepherd, Michael Ibba Jul 2013

Lipid Ii-Independent Trans Editing Of Mischarged Trnas By The Penicillin Resistance Factor Murm, Jennifer Shepherd, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Streptococcus pneumoniae is a causative agent of nosocomial infections such as pneumonia, meningitis, and septicemia. Penicillin resistance in S. pneumoniae depends in part upon MurM, an aminoacyl-tRNA ligase that attaches l-serine or l-alanine to the stem peptide lysine of Lipid II in cell wall peptidoglycan. To investigate the exact substrates the translation machinery provides MurM, quality control by alanyl-tRNA synthetase (AlaRS) was investigated. AlaRS mischarged serine and glycine to tRNAAla, as observed in other bacteria, and also transferred alanine, serine, and glycine to tRNAPhe. S. pneumoniae tRNAPhe has an unusual U4:C69 mismatch in its acceptor stem that …


Effect Of Shear Stress On Ecnos Expression And Dilation In Soleus Feed Arteries, Blanca Perez, Jay L. Brewster, Jeffrey Jasperse Jul 2013

Effect Of Shear Stress On Ecnos Expression And Dilation In Soleus Feed Arteries, Blanca Perez, Jay L. Brewster, Jeffrey Jasperse

Featured Research

Shear stress causes artery dilation and increased expression of endothelial cell nitric oxide synthase (ecNOS) in coronary and placental arteries. We sought to determine the importance of shear stress in maintaining normal dilation and normal levels of ecNOS in rat soleus feed arteries (SFA). SFA were isolated from male Sprague-Dawley rats and cannulated for in vitro microscopy (Fig. 6). SFA were exposed to no shear stress, low shear stress, or high shear stress conditions for 4 hours. After 4 hours, endothelium-dependent dilation (acetylcholine: ACh) and endothelium-independent dilation (sodium nitroprusside: SNP) were tested. Arteries were then uncannulated, mRNA was isolated, and …


Modeling The Influence Of Vitamin D Deficiency On Cigarette Smoke-Induced Emphysema, Mardi A. Crane-Godreau, Candice C. Black, Andrew J. Giustini, Tenzin Dechen, Jihan Ryu, James A. Jukosky, Hong-Kee Lee, Katherine Bessette, Nora R. Ratcliffe, P. Jack Hoopes, Steven Fiering, John A. Kelly, J. C. Leiter Jun 2013

Modeling The Influence Of Vitamin D Deficiency On Cigarette Smoke-Induced Emphysema, Mardi A. Crane-Godreau, Candice C. Black, Andrew J. Giustini, Tenzin Dechen, Jihan Ryu, James A. Jukosky, Hong-Kee Lee, Katherine Bessette, Nora R. Ratcliffe, P. Jack Hoopes, Steven Fiering, John A. Kelly, J. C. Leiter

Dartmouth Scholarship

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. While the primary risk factor for COPD is cigarette smoke exposure, vitamin D deficiency has been epidemiologically implicated as a factor in the progressive development of COPD-associated emphysema. Because of difficulties inherent to studies involving multiple risk factors in the progression of COPD in humans, we developed a murine model in which to study the separate and combined effects of vitamin D deficiency and cigarette smoke exposure. During a 16-week period, mice were exposed to one of four conditions, control diet breathing room air (CD-NS), control …


Nuclear Localization Of Cpi-17, A Protein Phosphatase-1 Inhibitor Protein, Affects Histone H3 Phosphorylation And Corresponds To Proliferation Of Cancer And Smooth Muscle Cells., Masumi Eto, Jason A Kirkbride, Rishika Chugh, Nana Kofi Karikari, Jee In Kim Apr 2013

Nuclear Localization Of Cpi-17, A Protein Phosphatase-1 Inhibitor Protein, Affects Histone H3 Phosphorylation And Corresponds To Proliferation Of Cancer And Smooth Muscle Cells., Masumi Eto, Jason A Kirkbride, Rishika Chugh, Nana Kofi Karikari, Jee In Kim

Department of Molecular Physiology and Biophysics Faculty Papers

CPI-17 (C-kinase-activated protein phosphatase-1 (PP1) inhibitor, 17kDa) is a cytoplasmic protein predominantly expressed in mature smooth muscle (SM) that regulates the myosin-associated PP1 holoenzyme (MLCP). Here, we show CPI-17 expression in proliferating cells, such as pancreatic cancer and hyperplastic SM cells. Immunofluorescence showed that CPI-17 was concentrated in nuclei of human pancreatic cancer (Panc1) cells. Nuclear accumulation of CPI-17 was also detected in the proliferating vascular SM cell culture and cells at neointima of rat vascular injury model. The N-terminal 21-residue tail domain of CPI-17 was necessary for the nuclear localization. Phospho-mimetic Asp-substitution of CPI-17 at Ser12 attenuated the nuclear …


Divergent Protein Motifs Direct Ef-P Mediated Translational Regulation In Salmonella And Escherichia Coli, Steven J. Hersch, Mengchi Wang, S. Betty Zou, Kyung-Mee Moon, Leonard J. Foster, Michael Ibba, William Wiley Navarre Apr 2013

Divergent Protein Motifs Direct Ef-P Mediated Translational Regulation In Salmonella And Escherichia Coli, Steven J. Hersch, Mengchi Wang, S. Betty Zou, Kyung-Mee Moon, Leonard J. Foster, Michael Ibba, William Wiley Navarre

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is a universally conserved bacterial translation factor homologous to eukaryotic/archaeal initiation factor 5A. In Salmonella, deletion of the efp gene results in pleiotropic phenotypes, including increased susceptibility to numerous cellular stressors. Only a limited number of proteins are affected by the loss of EF-P, and it has recently been determined that EF-P plays a critical role in rescuing ribosomes stalled at PPP and PPG peptide sequences. Here we present an unbiased in vivo investigation of the specific targets of EF-P by employing stable isotope labeling of amino acids in cell culture (SILAC) to compare the …


Intrinsic Apoptotic Pathway: Effects Of Calcium On Murine Cytochrome C Release In Brain And Liver Mitochondria, Dane M. Edwards Apr 2013

Intrinsic Apoptotic Pathway: Effects Of Calcium On Murine Cytochrome C Release In Brain And Liver Mitochondria, Dane M. Edwards

Senior Honors Theses

A cell may use one of three main apoptotic pathways leading to programmed cell death: the extrinsic pathway, the perforin/granzyme pathway and the intrinsic pathway. The most pertinent to this discussion is the intrinsic pathway, which utilizes the mitochondria as an essential intermediary. Mitochondria’s primary function in relation to this pathway is the subsequent release of pro-apoptotic factors including cytochrome c, which activate a caspase cascade leading to the death of the cell. Cytochrome c is released partly due to an increase in cytosolic calcium levels. Two methods of the release of cytochrome c have been proposed. The first is …


Improved Tolerance To Salt And Water Stress In Drosophila Melanogaster Cells Conferred By Late Embryogenesis Abundant Protein., Matthew Marunde, Dilini Samarajeewa, John Anderson, Shumin Li, Steven Hand, Michael Menze Apr 2013

Improved Tolerance To Salt And Water Stress In Drosophila Melanogaster Cells Conferred By Late Embryogenesis Abundant Protein., Matthew Marunde, Dilini Samarajeewa, John Anderson, Shumin Li, Steven Hand, Michael Menze

Faculty Scholarship

Mechanisms that govern anhydrobiosis involve the accumulation of highly hydrophilic macromolecules, such as late embryogenesis abundant (LEA) proteins. Group 1 LEA proteins comprised of 181 (AfLEA1.1) and 197 (AfLEA1.3) amino acids were cloned from embryos of Artemia franciscana and expressed in Drosophila melanogaster cells (Kc167). Confocal microscopy revealed a construct composed of green fluorescence protein (GFP) and AfLEA1.3 accumulates in the mitochondria (AfLEA1.3-GFP), while AfLEA1.1-GFP was found in the cytoplasm. In the presence of mixed substrates, oxygen consumption was statistically identical for permeabilized Kc167 control and Kc167-AfLEA1.3 cells. Acute titrations of permeabilized cells with NaCl up to 500 mM led …


Small Interfering Rna-Mediated Translation Repression Alters Ribosome Sensitivity To Inhibition By Cycloheximide In Chlamydomonas Reinhardtii, Xinrong Ma Apr 2013

Small Interfering Rna-Mediated Translation Repression Alters Ribosome Sensitivity To Inhibition By Cycloheximide In Chlamydomonas Reinhardtii, Xinrong Ma

School of Biological Sciences: Dissertations, Theses, and Student Research

RNA interference (RNAi) is an evolutionarily conserved gene silencing mechanism in eukaryotes, with regulatory roles in a variety of biological processes, including cell cycle, cell differentiation, physiological and metabolic pathways, and stress responses. RNAi can function by transcriptional silencing, mRNA target cleavage, translation repression and/or DNA elimination. In this study, we used the unicellular green alga Chlamydomonas reinhardtii as a model system to study RNAi-mediated translation repression. We demonstrated that small RNAs (sRNAs) generated from exogenously introduced inverted repeat transgenes, with perfect complementarity to the 3’UTR of a target transcript, can inhibit protein synthesis, without or with only minimal mRNA …


Locating The Modifier Of Segregation Distorter In Drosophila Melanogaster, Samuel Craven Apr 2013

Locating The Modifier Of Segregation Distorter In Drosophila Melanogaster, Samuel Craven

Honors Program Projects

The Drosophila melanogaster meiotic drive system Segregation Distorter (SD) has been a topic of great interest over the past decades due to its implications for fertility issues in fruit flies and other species as well. Several genes have been associated with this system; however, little research has focused on a particular one of these genes—the Modifier of SD. The location of this modifier gene is still unknown, so multiple deleted segments of DNA that compose a suspect area along the 2nd chromosome were tested here to see if some level of distortion is established in the absence of these segments. …


Maintenance Of Mitochondrial Genomic Integrity In The Absence Of Manganese Superoxide Dismutase In Mouse Liver Hepatocytes., Anthony R. Cyr, Kyle E. Brown, Michael L. Mccormick, Mitchell C. Coleman, Adam J. Case, George S. Watts, Bernard W. Futscher, Douglas R. Spitz, Frederick E. Domann Feb 2013

Maintenance Of Mitochondrial Genomic Integrity In The Absence Of Manganese Superoxide Dismutase In Mouse Liver Hepatocytes., Anthony R. Cyr, Kyle E. Brown, Michael L. Mccormick, Mitchell C. Coleman, Adam J. Case, George S. Watts, Bernard W. Futscher, Douglas R. Spitz, Frederick E. Domann

Journal Articles: Cellular & Integrative Physiology

Manganese superoxide dismutase, encoded by the Sod2 gene, is a ubiquitously expressed mitochondrial antioxidant enzyme that is essential for mammalian life. Mice born with constitutive genetic knockout of Sod2 do not survive the neonatal stage, which renders the longitudinal study of the biochemical and metabolic effects of Sod2 loss difficult. However, multiple studies have demonstrated that tissue-specific knockout of Sod2 in murine liver yields no observable gross pathology or injury to the mouse. We hypothesized that Sod2 loss may have sub-pathologic effects on liver biology, including the acquisition of reactive oxygen species-mediated mitochondrial DNA mutations. To evaluate this, we established …


Improved Tolerance To Salt And Water Stress In Drosophila Melanogaster Cells Conferred By Late Embryogenesis Abundant Protein, Matthew R. Marunde, Dilini A. Samarajeewa, John Anderson, Shumin Li, Steven C. Hand, Michael A. Menze Jan 2013

Improved Tolerance To Salt And Water Stress In Drosophila Melanogaster Cells Conferred By Late Embryogenesis Abundant Protein, Matthew R. Marunde, Dilini A. Samarajeewa, John Anderson, Shumin Li, Steven C. Hand, Michael A. Menze

Faculty Research & Creative Activity

Mechanisms that govern anhydrobiosis involve the accumulation of highly hydrophilic macromolecules, such as late embryogenesis abundant (LEA) proteins. Group 1 LEA proteins comprised of 181 (AfLEA1.1) and 197 (AfLEA1.3) amino acids were cloned from embryos of Artemia franciscana and expressed in Drosophila melanogaster cells (Kc167). Confocal microscopy revealed a construct composed of green fluorescence protein (GFP) and AfLEA1.3 accumulates in the mitochondria (AfLEA1.3-GFP), while AfLEA1.1-GFP was found in the cytoplasm. In the presence of mixed substrates, oxygen consumption was statistically identical for permeabilized Kc167 control and Kc167-AfLEA1.3 cells. Acute titrations of permeabilized cells with NaCl up to 500 mM led …


Diapause And Anhydrobiosis In Embryos Of Artemia Franciscana: Metabolic Depression, Lea Proteins And Water Stress, Steven C. Handel, Yuvraj Patil, Shumin Li, Nilay Chakraborty, Apurva Borcar, Michael A. Menze, Leaf C. Boswell, Daniel Moore, Mehmet Toner Jan 2013

Diapause And Anhydrobiosis In Embryos Of Artemia Franciscana: Metabolic Depression, Lea Proteins And Water Stress, Steven C. Handel, Yuvraj Patil, Shumin Li, Nilay Chakraborty, Apurva Borcar, Michael A. Menze, Leaf C. Boswell, Daniel Moore, Mehmet Toner

Faculty Research & Creative Activity

Metabolic depression is typically correlated with extended survival of environmental challenge and energy-limitation in early life stages of various invertebrates and vertebrates. Diapause is an ontogenetically-programmed reduction of development and often metabolism seen in many invertebrates. When embryos of Artemia franciscana enter the state of diapause, the overall metabolic depression is estimated to be greater than 99%. These embryos also contain trehalose and express multiple isoforms of Late Embryogenesis Abundant (LEA) proteins, constituents often present in a number of such anhydrobiotic animals. The mRNA levels for LEA proteins are highest in diapause and post-diapause embryos that possess desiccation tolerance, but …


Diapause And Anhydrobiosis In Embryos Of Artemia Franciscana : Metabolic Depression, Lea Proteins And Water Stress., Steven Handel, Yuvraj Patil, Shumin Li, Nilay Charkraborty, Arpurva Borcar, Michael Menze, Leaf Boswell, Daniel Moore, Mehmet Toner Jan 2013

Diapause And Anhydrobiosis In Embryos Of Artemia Franciscana : Metabolic Depression, Lea Proteins And Water Stress., Steven Handel, Yuvraj Patil, Shumin Li, Nilay Charkraborty, Arpurva Borcar, Michael Menze, Leaf Boswell, Daniel Moore, Mehmet Toner

Faculty Scholarship

Metabolic depression is typically correlated with extended survival of environmental challenge and energy-limitation in early life stages of various invertebrates and vertebrates. Diapause is an ontogenetically-programmed reduction of development and often metabolism seen in many invertebrates. When embryos of Artemia franciscana enter the state of diapause, the overall metabolic depression is estimated to be greater than 99%. These embryos also contain trehalose and express multiple isoforms of Late Embryogenesis Abundant (LEA) proteins, constituents often present in a number of such anhydrobiotic animals. The mRNA levels for LEA proteins are highest in diapause and post-diapause embryos that possess desiccation tolerance, but …