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Full-Text Articles in Life Sciences
Amblyomma Maculatum Secis Binding Protein 2 And Putative Selenoprotein P Are Indispensable For Pathogen Replication And Tick Fecundity, Khemraj Budachetri, Gary Crispell, Shahid Karim
Amblyomma Maculatum Secis Binding Protein 2 And Putative Selenoprotein P Are Indispensable For Pathogen Replication And Tick Fecundity, Khemraj Budachetri, Gary Crispell, Shahid Karim
Faculty Publications
Selenium, a vital trace element, is incorporated into selenoproteins to produce selenocysteine. Our previous studies have revealed an adaptive co-evolutionary process that has enabled the spotted fever-causing tick-borne pathogen Rickettsia parkeri to survive by manipulating an antioxidant defense system associated with selenium, which includes a full set of selenoproteins and other antioxidants in ticks. Here, we conducted a systemic investigation of SECIS binding protein 2 (SBP2) and putative selenoprotein P (SELENOP) by transcript silencing in adult female Gulf-coast ticks (Amblyomma maculatum). Knockdown of the SBP2 and SELENOP genes depleted the respective transcript levels of these tick selenogenes, and …
Assessment Of Tick Antioxidant Responses To Exogenous Oxidative Stressors And Insight Into The Role Of Catalase In The Reproductive Fitness Of The Gulf Coast Tick, Amblyomma Maculatum, D. Kumar, K. Budachetri, V.C. Meyers, Shahid Karim
Assessment Of Tick Antioxidant Responses To Exogenous Oxidative Stressors And Insight Into The Role Of Catalase In The Reproductive Fitness Of The Gulf Coast Tick, Amblyomma Maculatum, D. Kumar, K. Budachetri, V.C. Meyers, Shahid Karim
Faculty Publications
As obligate blood‐sucking ectoparasites, to avoid tissue damage, ticks must neutralize the reactive oxygen species (ROS) generated from uptake and digestion of a bloodmeal. Consequently, ticks utilize a battery of antioxidant molecules, including catalase (CAT), an enzyme that converts hydrogen peroxide (H2O2) into water and oxygen. Here, we investigated the tick antioxidant machinery by exogenous injection of sublethal doses of H2O2 or paraquat. The relative transcript levels of selected Amblyomma maculatum antioxidant targets in tissues were determined by quantitative reverse transcriptase PCR following treatment. The results showed 2–16‐fold increases in target antioxidant gene …
An Insight Into The Functional Role Of Thioredoxin Reductase, A Selenoprotein, In Maintaining Normal Native Microbiota In The Gulf Coast Tick (Ambylomma Maculatum), Khemraj Budachetri, Shahid Karim
An Insight Into The Functional Role Of Thioredoxin Reductase, A Selenoprotein, In Maintaining Normal Native Microbiota In The Gulf Coast Tick (Ambylomma Maculatum), Khemraj Budachetri, Shahid Karim
Faculty Publications
Tick selenoproteins have been associated with antioxidant activity in ticks. Thioredoxin reductase (TrxR), also a selenoprotein, belongs to the pyridine nucleotide‐disulphide oxidoreductase family of proteins and is an important antioxidant. Molecular interactions between native microbiota and tick hosts have barely been investigated to date. In this study, we determined the functional role of TrxR in tick feeding and in maintenance of the native microbial community. TrxR transcript levels remained high and microbial load was reduced throughout tick attachment to the vertebrate host. RNA interference (RNAi) showed that depletion of TrxR activity did not interfere with tick haematophagy or phenotype but …
An Insight Into The Microbial Diversity And Expression Of Cysteine Protease Inhibitors (Cystatin) In Rickettsia Parkeri Infected Amblyomma Maculatum, Khemraj Budachetri
An Insight Into The Microbial Diversity And Expression Of Cysteine Protease Inhibitors (Cystatin) In Rickettsia Parkeri Infected Amblyomma Maculatum, Khemraj Budachetri
Master's Theses
Amblyomma maculatum (Gulf Coast tick) is an emerging tick species of public health significance in United States. It is a competent vector of Rickettsia parkeri, an etiological agent of a human rickettsiosis. In this study, we investigated the spotted fever group of rickettsial diversity in A. maculatum based on rickettsial ompA gene PCR. Our results showed A. maculatum harbors R. parkeri, R. amblyommii, and R. endosymbiont of A. maculatum. While only R. parkeri was detected in female salivary glands which suggest its ability to traffic from midgut to salivary glands via hemocoel. The presence of R. parkeri was further …
Rna Interference-Mediated Depletion Of N-Ethylmaleimide Sensitive Fusion Protein And Synaptosomal Associated Protein Of 25 Kda Results In The Inhibition Of Blood Feeding Of The Gulf Coast Tick, Amblyomma Maculatum, Rebecca Browning, Shahid Karim
Rna Interference-Mediated Depletion Of N-Ethylmaleimide Sensitive Fusion Protein And Synaptosomal Associated Protein Of 25 Kda Results In The Inhibition Of Blood Feeding Of The Gulf Coast Tick, Amblyomma Maculatum, Rebecca Browning, Shahid Karim
Faculty Publications
The signalling pathways in tick salivary glands that control ‘sialo‐secretome’ secretion at the tick−host interface remain elusive; however, this complex process is essential for successful feeding and manipulation of the host haemostatic response. Exocytosis of the sialo‐secretome in the salivary glands requires a core of soluble N‐ethylmaleimide‐sensitive fusion (NSF) attachment proteins (SNAPs) and receptor proteins (SNAREs). SNAREs have been identified as the key components in regulating the sialo‐secretome in the salivary gland cells. In this study, we utilized RNA interference to investigate the functional role of two Amblyomma maculatum SNARE complex proteins, AmNSF and AmSNAP‐25, in the tick salivary glands …
Molecular Characterization And Functional Significance Of The Vti Family Of Snare Proteins In Tick Salivary Glands, Ashley M. Villarreal, Steven W. Adamson, Rebecca E. Browning, Khemraj Budachetri, Muhammad Sohail Sajid, Shahid Karim
Molecular Characterization And Functional Significance Of The Vti Family Of Snare Proteins In Tick Salivary Glands, Ashley M. Villarreal, Steven W. Adamson, Rebecca E. Browning, Khemraj Budachetri, Muhammad Sohail Sajid, Shahid Karim
Faculty Publications
Exocytosis involves membrane fusion between secretory vesicles and the plasma membrane. The Soluble N-ethylmaleimide-sensitive factor attachment proteins (SNAPs) and their receptor proteins (SNAREs) interact to fuse vesicles with the membrane and trigger the release of their sialosecretome out of the tick salivary gland cells. In this study, we examined the functional significance of the Vti family of SNARE proteins of blood-feeding Amblyomma maculatum and Amblyomma americanum. Vti1A and Vti1B have been implicated in multiple functional roles in vesicle transport. QRT-PCR studies demonstrated that the highest transcriptional expression of vti1a and vti1b genes occurs in unfed salivary glands, suggesting that …