Structural Characterization of the C-terminus of the Cochlear Motor Protein Prestin: Intrinsic Disorder Linked to Voltage Sensor Function

The sensitivity of mammalian hearing relies upon the ability to amplify sound. Outer hair cells (OHCs) in the cochlea have motile properties that support this function. The motor protein called prestin resides in the lateral wall of the OHCs. Prestin undergoes voltage-dependent conformational changes, which correlates to the movement of charge through the membrane or non-linear capacitance (NLC). This property underlies OHC electromotility. A mechanistic understanding of prestin’s function remains unknown. Previous research has tied prestin’s C-terminus (residues 499-799) to the voltage-dependent events that occur in the membrane. The folding and biochemical properties of prestin’s C-terminus were characterized. This information was used to probe the function of the C-terminus. Sequence analysis and limited proteolysis indicated that a 60-70 residue loop partitions the sulfate transporter and anti-sigma factor (STAS) domain in the C-terminus. To investigate the structural and functional role of the ‘loop’ (residues 571-635), the sequence was deleted (Δ) from prestin cDNA and transfected into HEK 293T cells. Whole-cell voltage clamp experiments confirmed that prestin Δ571-635 exhibited NLC; however, the voltage-capacitance curve had an increased slope-factor compared to wild type. This result suggested that the mutation affected the protein’s voltage sensor. The fact that the deletion protein exhibited NLC implies that the mutation did not adversely affect the structure. It was hypothesized that only a small subset of residues, attributed to the STAS domain, contribute to the structure in prestin’s C-terminus. To characterize the C-terminus structure, a series of mutant proteins were made with sequence deleted from the regions bordering the STAS domain. The implication being that the deletion would destabilize the protein if it disrupted important structure. On that premise, nuclear magnetic resonance spectroscopy (NMR), and analytical ultracentrifugation were used to characterize the folding and stability of the deletion mutants. The results showed that the deletion mutants existed as folded, monomeric proteins in solution. Interestingly, several of the proteins displayed an ensemble of folding conformations that ranged from compact/globular to prolate/ellipsoid. Based on the deletions, the data suggests that the STAS domain consists of two subdomains (STAS A and STAS B) separated by a loop approximately 65 residues long. To understand the basis of the observed conformations, surface plasmon resonance (SPR) imaging determined whether binding occurs between the two subdomains. The data showed that the STAS A and B subdomains bind in a specific and reversible manner characterized by a slow on-rate with weak affinity. NMR data showed chemical shifts consistent with a folded protein; however, differences of peak intensity suggested that movement occurred within the structure of the C-terminus. The observations from the NMR and SPR studies appeared to be consistent with conformations observed from the analytical ultracentrifugation. In summary, the data suggests that the C-terminus contributes to the voltage sensor function. These behaviors of the protein in solution appear to be an innate feature of the C-terminus and may define the unique properties of prestin within the SLC26 protein family

Moisture conditions in coated wood panels during 18 months natural weathering at five sites in Europe

Wood moisture content of coated panels of Scots pine sapwood was recorded during 18 months natural weathering in Vienna by logging electric resistance and temperature near the surface. Eight coating systems with various film thicknesses were used, including three solvent borne alkyd stains, three water borne acrylic stains and two water borne acrylic paints. At five sites in Europe wood moisture content of panels coated with three solvent borne alkyd stains, a brow acrylic stain and a white opaque acrylic paint was recorded weekly by changes in panel mass. Fluctuations in wood moisture content were influenced by the film thickness, moisture protection and colour of the coating systems used. Degradation phenomena led to decreasing moisture protection of less durable coating systems over time of exposure. Differences between the exposure sites were relatively low, except the site in the UK where moisture conditions were higher

Geostatistical model of the spatial distribution of arsenic in groundwaters in Gujarat State, India

From Springer Nature via Jisc Publications RouterHistory: received 2019-12-15, accepted 2020-06-24, registration 2020-06-24, pub-electronic 2020-07-11, online 2020-07-11, pub-print 2021-07Publication status: PublishedFunder: Engineering and Physical Sciences Research Council; doi: http://dx.doi.org/10.13039/501100000266; Grant(s): IAA Impact AwardAbstract: Geogenic arsenic contamination in groundwaters poses a severe health risk to hundreds of millions of people globally. Notwithstanding the particular risks to exposed populations in the Indian sub-continent, at the time of writing, there was a paucity of geostatistically based models of the spatial distribution of groundwater hazard in India. In this study, we used logistic regression models of secondary groundwater arsenic data with research-informed secondary soil, climate and topographic variables as principal predictors generate hazard and risk maps of groundwater arsenic at a resolution of 1 km across Gujarat State. By combining models based on different arsenic concentrations, we have generated a pseudo-contour map of groundwater arsenic concentrations, which indicates greater arsenic hazard (> 10 μg/L) in the northwest, northeast and south-east parts of Kachchh District as well as northwest and southwest Banas Kantha District. The total number of people living in areas in Gujarat with groundwater arsenic concentration exceeding 10 μg/L is estimated to be around 122,000, of which we estimate approximately 49,000 people consume groundwater exceeding 10 µg/L. Using simple previously published dose–response relationships, this is estimated to have given rise to 700 (prevalence) cases of skin cancer and around 10 cases of premature avoidable mortality/annum from internal (lung, liver, bladder) cancers—that latter value is on the order of just 0.001% of internal cancers in Gujarat, reflecting the relative low groundwater arsenic hazard in Gujarat State

The Grizzly, November 4, 1996

Berman Exhibit Focuses on the Environment • Chemist Speaks on Authentication Processes • Dr. Borsdorf Lauded • Opinion: Future of America; Are we too Dependent on Computers?; Questions on Openness? • This Wednesday is Unity Day! • Shepherdson\u27s TD Run Lifts Ursinus Over Muhls • Men\u27s Soccer Loses Heartbreaker to Western Maryland • Field Hockey Loses Eighth Straight • Larkin Named Player of the Weekhttps://digitalcommons.ursinus.edu/grizzlynews/1390/thumbnail.jp

The Lantern Vol. 64, No. 1, Fall 1996

• Sleepwalk • Icky • Hauling the Load • Between Days • First Day • Slipping • College Roommates • Full Moon in Scorpio • Summer Madness • Learning French • nEverglades • The Way Around • Rain • Solacehttps://digitalcommons.ursinus.edu/lantern/1149/thumbnail.jp

The Lantern Vol. 62, No. 1, December 1994

• Hollow • A Little Knowledge is Dangerous • My Old Block • Life • The Natural Born Fool • Oracle • Formation of a Triangle • Marie on the Beach • The Tweed Derby • Tripping • In Vitro • The Character • Coming Home for Christmas • Unkempt • Too Much • Reimertanti-Ode • Seeds • Secrethttps://digitalcommons.ursinus.edu/lantern/1145/thumbnail.jp

The Grizzly, March 24, 1997

Alternative Spring Break Unites Students, Charity • Author Ntozake Shange Reads, Lectures in Olin • New Chair of Campus Ministries Committee • Wicks House to Open in Fall • Ursinus is Ranked Among Best Science Schools • Opinion: Some Advice to Mr. Leahy; All Good Things; Liberal Arts Education Part II, Awareness Weeks; Letters from Great Britain; Let\u27s Get it Straight; A Tree or not a Tree, That is the Question • Something Old, Something New, Something Borrowed, Something Blur • The Tempest: Wayfaring Weather • Lady Bears Lose ECAC Championship • Baseball Starts Season at 4-7 Pace • Women\u27s Lacrosse Wins Year\u27s First Contest • Men\u27s Tennis Falls to Moravian • Rhodenbaugh and Minnich Honored as SAAC Chairs • Softball Off to 10-4 Start • Torsone an All-American • Gymnastics Team Places 8th at Nationals • Women\u27s Tennis Wins • USA Wrestling Lineup Announcedhttps://digitalcommons.ursinus.edu/grizzlynews/1400/thumbnail.jp

The Grizzly, September 30, 1996

Helen Zia Speaks on Views of an Asian American Feminist • New Committee Formed to Reduce Vandalism • The 1996-1997 Freshman Class Officers • Graduate School Presentation to be Held Next Wednesday • Gilicinski addresses The Color of Atoms • Research Funding and Presentations • Opinions: My Kingdom for a Phone; War Cries Have Begun; Mourning Tupac Shakur; It\u27s Not Your Fault; Are There Elections This Year?; The Ruby is Not Dead • The S.U.N. is Rising • Family Day • Test Your Strength • Let\u27s Vacate and do Service! • Conserve, Conserve, Conserve! Using Your Energy to Save Energy • Powerful Voir Dire Presents Thought-Provoking Look at Society • Women\u27s Soccer Has Rough Week • Bears Win Fourth in a Row • Volleyball Finds Winning Ways • Men\u27s Soccer Falls to 3-6 • Field Hockey Nets First Winhttps://digitalcommons.ursinus.edu/grizzlynews/1386/thumbnail.jp

The Lantern Vol. 64, No. 2, Spring 1997

• Year\u27s End, with Resolutions • Addicted • Muerte, Carlos • Motions • At the Wyeth Gallery • Between Contexts • I\u27m Allowed (and More Nonsense) • Wall and Piece • Timekeeper\u27s Workspace • The Process • Second Sex: A Portrait of the Artist as a Woman • On the Side of the Road • Joe • To Matthew Arnold • A Deep Sleep on Hydrocodone • Madness of a Night • Return • The Sudden Grave • A Farce • Twists of Fur • Ambiguity • The Odor of Continuums • My Father\u27s Daughter • The Meaning of Life • I Aim to Tell • Nobody\u27s Fanhttps://digitalcommons.ursinus.edu/lantern/1150/thumbnail.jp