Life Sciences Commons^™

Continuous Mowing Differentially Affects Floral Defenses In The Noxious And Invasive Weed Solanum Elaeagnifolium In Its Native Range, Alejandro Vasquez, Alexa Alaniz, Robert K. Dearth, Rupesh R. Kariyat

Biology Faculty Publications and Presentations

In weeds, disturbance has been found to affect life history traits and mediate trophic interactions. In urban landscapes, mowing is an important disturbance, and we previously showed that continuous mowing leads to enhanced fitness and defense traits in Solanum elaeagnifolium, Silverleaf Nightshade (SLN). However, most studies have been focused on foliar defenses, ignoring floral defenses. In this study we examined whether continuous mowing affected floral defenses in SLN using mowed and unmowed populations in South Texas, their native range. We found flowers of mowed SLN plants larger but lighter than unmowed plants. Additionally, flowers on plants that were mowed …

Tarantula Toxin Transcripts And Toxin Structure Prediction By Alphafold, Christine Vega, Rebekkah Sepulveda, Ying Jia

Biology Faculty Publications and Presentations

Tarantula venom predominantly comprises peptides and small proteins (venom toxins). To explore this further, we generated a combined gland cDNA library from five different tarantula species. Subsequently we randomly sequenced 752 clones, which led to the identification of sixteen distinct toxin groups, including one novel group. Each group consists of a minimum of three identical sequences. A comprehensive analysis of these toxin groups was carried out, and we simulated the 3D structures of certain predicted toxins. These transcripts can be used to the production of venom toxins through recombinant techniques, offering promising applications in various biomedical applications.

Foxo1 Promotes The Expression Of Canonical Wnt Target Genes In Examined Basal-Like Breast And Glioblastoma Multiforme Cancer Cells, Shania Pintor, Alma Lopez, David Flores, Brianda Lozoya, Bipul Soti, Rishi Pokhrel, Joaquin Negrete, Michael W. Persans, Robert Gilkerson, Bonnie Gunn, Megan Keniry

Biology Faculty Publications and Presentations

Basal-like breast cancer (BBC) and glioblastoma multiforme (GBM) are aggressive cancers associated with poor prognosis. BBC and GBM have stem cell-like gene expression signatures, which are in part driven by forkhead box O (FOXO) transcription factors. To gain further insight into the impact of FOXO1 in BBC, we treated BT549 cells with AS1842856 and performed RNA sequencing. AS1842856 binds to unphosphorylated FOXO1 and inhibits its ability to directly bind to DNA. Gene Set Enrichment Analysis indicated that a set of WNT pathway target genes, including lymphoid enhancer-binding factor 1 (LEF1) and transcription factor 7 (TCF7), were …

Sex And Stress Modulate Pupal Defense Response In Tobacco Hornworm, Sukhman Singh, Sakshi Watts, Ishveen Kaur, Isabella Rodriguez, Jessica Ayala, Dariela Rodriguez, Elian Martin, Rupesh R. Kariyat

Biology Faculty Publications and Presentations

In insects, larval and adult defenses against predators have been well studied. However, pupal (also known as resting stage) defenses have been overlooked and not examined thoroughly. Although some pupa possess antipredator strategies such as hairs, spines, cryptic coloration, and exudation of chemicals, few studies have tested these responses and the factors affecting them. Here, we investigated the behavioral responses in tobacco hornworm Manduca sexta that pupates in soil by introducing an external stimulus using vibrations from an electric toothbrush to mimic predation. We observed that M. sexta made violent wriggling (twitching), followed by pulsating movements in response to the …

Dna Barcoding Of Springsnails (Mollusca, Gastropoda, Caenogastropoda) Endemic To The Trans-Pecos Region Of Texas (Usa), Kathryn E. Perez, Vanessa Saenz, Natalia Salazar-Lozano, Benjamin F. Schwartz, Benjamin T. Hutchins

Biology Faculty Publications and Presentations

In desert environments, unique communities depend on groundwater from springs, including a diverse radiation of small (<5 >mm) snails found in the desert across the southwestern United States. Nearly all springsnail species are considered critically imperiled with their existence depending on maintenance of spring-flows in regions of declining water availability. Extant, endemic springsnails in the Trans-Pecos region of Texas include one species of Pseudotryonia Hershler, 2001, five nominal Tryonia W. Stimpson, 1865 (Cochliopidae) and seven Pyrgulopsis Call & Pilsbry, 1886 (Hydrobiidae). Four of these are classified as endangered under the US Endangered Species Act. Surveys for springsnails were conducted at …

How Enhancers Regulate Wavelike Gene Expression Patterns, Christine Mau, Heike Rudolf, Frederic Strobl, Benjamin Schmid, Timo Regensburger, Ralf Palmisano, Ernst Hk Stelzer, Leila Taher, Ezzat El-Sherif

Biology Faculty Publications and Presentations

A key problem in development is to understand how genes turn on or off at the right place and right time during embryogenesis. Such decisions are made by non-coding sequences called ‘enhancers.’ Much of our models of how enhancers work rely on the assumption that genes are activated de novo as stable domains across embryonic tissues. Such a view has been strengthened by the intensive landmark studies of the early patterning of the anterior-posterior (AP) axis of the Drosophila embryo, where indeed gene expression domains seem to arise more or less stably. However, careful analysis of gene expression patterns in …

Biological Flora Of Coastal Freshwater And Brackish Marshes: Cladium Jamaicense Crantz, Richard Stalter, Robert I. Lonard

Biology Faculty Publications and Presentations

Cladium jamaicense Crantz, also known as sawgrass, has a broad distributional range from the Atlantic coast of Virginia to Florida, to southern Texas, the Caribbean, and along the Atlantic coast of Mexico to Central America, and to Brazil. Cladium jamaicense typically occurs in oligotrophic sloughs and fresh and brackish marshes where optimal salinity values range from 0 to 3.5 ppt. This species is a long-lived perennial with a highly developed rhizome system with rhizomes up to 20 cm long and 2.5 to 10 mm in diameter. Asexual reproduction is common. Its fibrous root system comprises short dauciform roots characterized by …

Habitat Use And Winter Site Fidelity Of Lincoln’S Sparrow (Melospiza Lincolnii) In The Lower Rio Grande Valley Of Texas, Timothy Brush, Hugh E. Conway, Catherine C. Brush

Biology Faculty Publications and Presentations

No abstract provided.

Pathogenicity Of Multiple Providencia Species (Enterobacteriales: Morganellaceae) To The Mass-Reared Mexican Fruit Fly (Diptera: Tephritidae), Bacilio Salas, Hugh E. Conway, Don C. Vacek, Christopher Vitek, Erin Schuenzel

Biology Faculty Publications and Presentations

Mexican fruit fly (Anastrepha ludens (Loew)) (Diptera: Tephritidae) represents a major threat to fruit production in the Western Hemisphere. Sterile insect technique is used to suppress and eradicate wild populations. Success of this control method necessitates weekly production of hundreds of millions of flies, their sterilization by irradiation, and their aerial release. Diet needed to produce large fly numbers are conducive to the spread of bacteria. Pathogenic bacteria were isolated from 3 rearing facilities and from multiple sources: eggs, larvae, pupae and spent diet, and were found to include some isolates identified to the genus Providencia (Enterobacteriales: Morganellaceae). We …

Microbial Associations With Metcalf’S Tryonia, Tryonia Metcalfi (Gastropoda: Cochliopidae), An Imperiled Ci´Enega Endemic, Russell L. Minton, Kathryn E. Perez

Biology Faculty Publications and Presentations

The Chihuahuan Desert swamps are a hotspot for imperiled organisms including freshwater springsnails and bacteria. Many of these taxa are endemic to the desert and to the individual waterbodies where they occur. Efforts to conserve diversity in these threatened areas must account for the life history of the organisms, but also interactions between organisms including microbes. We documented the microbial assemblage associated with Tryonia metcalfi, a critically imperiled freshwater snail endemic to a ciénega system in western Texas. We identified 14 bacterial families in our snail samples and determined a core assemblage of 19 bacterial taxa (4 of which …

Detection Of A Diverse Endophyte Assemblage Within Fungal Communities Associated With The Arundo Leaf Miner, Lasioptera Donacis (Diptera: Cecidomyiidae), Marie-Claude Bon, John A. Goolsby, Guy Mercadier, Fatiha Guermache, Javid Kashef, Massimo Cristofaro, Ann T. Vacek, Alan Kirk

Biology Faculty Publications and Presentations

The larvae of Lasioptera donacis Coutin feed on fungal communities lining galleries within the mesophyll of leaf sheaths of Arundo donax in an aggregative manner. It has been stated that L. donacis could have established a fundamental symbiotic relationship with one fungus, although the fungal composition of these communities remains unsettled. Using a culture-dependent approach and ITS sequencing, the present work characterizes and compares the fungal communities associated with L. donacis in Eurasia with the endophytes of A. donax in Texas where L. donacis is absent. The 65 cultivable isolates obtained from L. donacis fungal communities were sorted into 15 …

Morphological Characterization Of Intraspecific Variation For Trichome Traits In Tomato (Solanum Lycopersicum), Satinderpal Kaur, Neetu Khanal, Robert K. Dearth, Rupesh R. Kariyat

Biology Faculty Publications and Presentations

Trichomes, the hairlike protuberances in plants, have been well known to act as the first line of defense against herbivores, and abiotic stresses, along with other structural defenses such as spines, thorns, and waxes. We previously reported the tremendous variation in trichome traits among different wild and cultivated Solanum species and demonstrated that trichomes types and density are traditionally miscalculated and often misnamed. However, intraspecific variation in trichome traits is poorly understood, although this has implications for stress tolerance and resistance breeding programs in economically important crop species and can also mediate ecological interactions at multiple trophic levels in their …

Predicting The Impact Of Climate Change On The Distribution Of Rhipicephalus Sanguineus In The Americas, Marcos Sánchez Pérez, Teresa Patricia Feria-Arroyo, Crystian Sadiel Venegas Barrera, Carolina Sosa-Gutiérrez, Javier Torres, Katherine A. Brown, Guadalupe Gordillo Pérez

Biology Faculty Publications and Presentations

Climate change may influence the incidence of infectious diseases including those transmitted by ticks. Rhipicephalus sanguineus complex has a worldwide distribution and transmits Rickettsial infections that could cause high mortality rates if untreated. We assessed the potential effects of climate change on the distribution of R. sanguineus in the Americas in 2050 and 2070 using the general circulation model CanESM5 and two shared socioeconomic pathways (SSPs), SSP2-4.5 (moderate emissions) and SSP2-8.5 (high emissions). A total of 355 occurrence points of R. sanguineus and eight uncorrelated bioclimatic variables were entered into a maximum entropy algorithm (MaxEnt) to produce 50 replicates per …

Greenbug Feeding-Induced Resistance To Sugarcane Aphids In Sorghum, Heena Puri, Edith Ikuze, Jessica Ayala, Isabella Rodriguez, Rupesh R. Kariyat, Joe Louis, Sajjan Grover

Biology Faculty Publications and Presentations

Plants are attacked by multiple insect pest species and insect herbivory can alter plant defense mechanisms. The plant defense responses to a specific herbivore may also contribute to the herbivore growth/survival on plants. Feeding by one insect species can modulate the plant defenses, which can either facilitate or hamper the colonization of subsequent incoming insects. However, little is known about the effect of sequential herbivory on sorghum plants. In this study, we demonstrate that a specialist aphid, sugarcane aphid (SCA; Melanaphis sacchari) grows faster on sorghum than a generalist aphid species, greenbug (GB; Schizaphis graminum). We also determined …

Effective Farm Management Promotes Native Amf And Benefit Organic Farming Systems, Pushpa Soti, Rupesh R. Kariyat, Alexis Racelis

Biology Faculty Publications and Presentations

Highlights

• Agricultural practices have significant influence on the AMF community dynamics.

• Soil nutrients regulate AMF spore abundance and diversity.

• Using grass cover crops can promote native AMF in farms.

Abstract

Using soil inoculants containing naturally occurring beneficial microorganisms has become a popular practice in sustainable agriculture. However, an understanding of the environmental variables that affect plant-microbe interactions and the benefit of using commercial inoculum is relatively sparse. To address this, we examined the efficiency of three different methods to inoculate AMF (Arbuscular Mycorrhizal Fungi) in organic vegetable farms in south Texas: cover cropping, application of farm-produced (indigenous) AMF inoculum, …

Evidence Of An Established Population Of Cherax Quadricarinatus (Von Martens, 1868) In South Texas, Usa, Adam Sanjar, Drew R. Davis, Richard J. Kline

Biology Faculty Publications and Presentations

Cherax quadricarinatus (von Martens, 1868) is a large parastacid crayfish (Decapoda: Parastacidae) native to Australia and Papua New Guinea. Due to various factors, C. quadricarinatus is an emerging invasive species in an increasing number of regions across the world. Deleterious ecological effects of C. quadricarinatus introduction have been documented in many of these regions, and its spread has been monitored and restricted where possible. Previously, only a small, isolated population of C. quadricarinatus in southern California had been reported within the continental United States. Here, we report the collection of three adult C. quadricarinatus from Brownsville, Cameron County, Texas, the …

The Known And Unknowns Of Aphid Biotypes, And Their Role In Mediating Host Plant Defenses, Neetu Khanal, Christopher Vitek, Rupesh R. Kariyat

Biology Faculty Publications and Presentations

Insect species are subjected to disparate selection pressure due to various biotic and abiotic stresses. Management practices including the heavy use of chemical insecticides and introduction of insect-resistant plant cultivars have been found to accelerate these processes. Clearly, natural selection coupled with human intervention have led to insect adaptations that alter phenotypes and genetic structure over time, producing distinct individuals with specialized traits, within the populations, commonly defined as biotypes. Biotypes are commonly found to have better fitness in the new environment and, in the case of aphids, the most commonly studied system for biotypes, have the ability to successfully …

Diel Activity Patterns Of Vector Mosquito Species In The Urban Environment: Implications For Vector Control Strategies, André Barretto B. Wilke, Adequate Mhlanga, Allisandra G. Kummer, Chalmers Vasquez, Maday Moreno, William D. Petrie, Art Rodriguez, Christopher Vitek, Gabriel L. Hamer, John-Paul Mutebi, Marco Ajelli

Biology Faculty Publications and Presentations

Mathematical models have been widely used to study the population dynamics of mosquitoes as well as to test and validate the effectiveness of arbovirus outbreak responses and mosquito control strategies. The objective of this study is to assess the diel activity of mosquitoes in Miami-Dade, Florida, and Brownsville, Texas, the most affected areas during the Zika outbreak in 2016–2017, and to evaluate the effectiveness of simulated adulticide treatments on local mosquito populations. To assess variations in the diel activity patterns, mosquitoes were collected hourly for 96 hours once a month from May through November 2019 in Miami-Dade County, Florida, and …

Revisiting Plant Defense-Fitness Trade-Off Hypotheses Using Solanum As A Model Genus, Sakshi Watts, Satinderpal Kaur, Rupesh R. Kariyat

Biology Faculty Publications and Presentations

Plants possess physical and chemical defenses which have been found to deter herbivores that feed and oviposit on them. Despite having wide variety of defenses which can be constitutive or induced, plants are attacked and damaged by insects associated with different mouthparts and feeding habits. Since these defenses are costly, trade-offs for growth and defense traits play an important role in warding off the herbivores, with consequences for plant and herbivore growth, development and fitness. Solanum is a diverse and rich genus comprising of over 1,500 species with economic and ecological importance. Although a large number of studies on Solanum …

The Justice Challenge: Honors Endeavors Innovative Pedagogies Through The Grand Challenge Scholars Program, Jonathan Kotinek, Rebecca C. Bott-Knutson, Leigh E. Fine, Joy L. Hart, William Ziegler, Paul Knox, Timothy Nichols, Susan Sumner, Heidi Appel, Mark C. Andersen

Biology Faculty Publications and Presentations

Honors practitioners from fourteen colleges and programs across the country at land-grant, public, and minority-serving institutions partner with agricultural experts to secure a United States Department of Agriculture (USDA) Higher Education Challenge grant focused on the themes of food justice, climate justice, and sustainable agriculture. Authors describe the program’s origin, objectives, and curricular outgrowths, highlighting its efficacy for empowering students in areas of systems thinking, career readiness, leadership in the service of addressing social needs, and learning through civic engagement.

The Foxo1 Inhibitor As1842856 Triggers Apoptosis In Glioblastoma Multiforme And Basal-Like Breast Cancer Cells, David Flores, Alma Lopez, Shreya Udawant, Bonnie Gunn, Megan Keniry

Biology Faculty Publications and Presentations

Basal-like breast cancer (BBC) and glioblastoma multiforme (GBM) are poor-prognosis cancers that lack effective targeted therapies and harbor embryonic stem gene expression signatures. Recently, our group and others found that forkhead box transcription factor FOXO1 promotes stem gene expression in BBC and GBM cell lines. Given the critical role of cancer stem cells in promoting cancer progression, we examined the impact of FOXO1 inhibition with AS1842856 (a cell-permeable small molecule that directly binds to unphosphorylated FOXO1 protein to block transcriptional regulation) on BBC and GBM cell viability. We treated a set of BBC and GBM cancer cell lines with increasing …

Are Epicuticular Waxes A Surface Defense Comparable To Trichomes? A Test Using Two Solanum Species And A Specialist Herbivore., Sakshi Watts, Rupesh R. Kariyat

Biology Faculty Publications and Presentations

Although plants possess a suite of structural defenses, most studies have focused on trichomes. Trichomes can have both pre- and post-ingestive effects and have been consistently found to reduce herbivory. Along with trichomes, a few studies have focused on epicuticular waxes as an important defense; however, manipulated comparisons examining herbivore growth and development is limited. In this study, using two Solanum species (Solanum glaucescens and Solanum macrocarpon) that vary in both defenses, we tested the hypothesis that variation in defenses will affect herbivore feeding, primarily by restricting feeding commencement. We used electron microscopy together with a series of plant- and …

The Photochemical Evolution Of Polycyclic Aromatic Hydrocarbons And Nontronite Clay On Early Earth And Mars, Nina Kopacz, Maria Angela Corazzi, Giovanni Poggiali, Ayla Von Essen, Vincent Kofman, Teresa Fornaro, Hugo Van Ingen, Eloi Camprubi, Helen E. King, John Brucato, Inge Loes Ten Kate

Biology Faculty Publications and Presentations

The photochemical evolution of polycyclic aromatic hydrocarbons (PAHs), an abundant form of meteoritic organic carbon, is of great interest to early Earth and Mars origin-of-life studies and current organic molecule detection efforts on Mars. Fe-rich clay environments were abundant on early Earth and Mars, and may have played a role in prebiotic chemistry, catalyzing the breakdown of PAHs and freeing up carbon for subsequent chemical complexification. Current Mars is abundant in clay-rich environments, which are most promising for harboring organic molecules and have comprised the main studied features by the Curiosity rover in search of them. In this work we …

Nilgai, Boselaphus Tragocamelus And White-Tailed Deer, Odocoileus Virginianus Use Of Water Troughs With And Without Remotely Operated Field Sprayers For Potential Treatment Of Cattle Fever Ticks, John A. Goolsby, Mauricio Cruz, Reyes Garcia Iii, Lauren P. Maestas, Teresa Patricia Feria-Arroyo

Biology Faculty Publications and Presentations

Nilgai antelope, Boselaphus tragocamelus and white-tailed deer (WTD), Odocoileus virginianus are hosts of cattle fever ticks, Rhipicephalus (=Boophilus) microplus, in the Lower Rio Grande Valley of South Texas. Daily use of water troughs and ponds were observed to determine if these locations could be used for field treatment methods for cattle fever ticks using remotely operated field sprayers. Game cameras (n=16) were deployed between June 2020 and September 2022 at two private ranches in Cameron County, TX. Both nilgai and WTD visited water troughs equipped with motion detecting sprayers in similar numbers to ponds, but numbers of animal visits were …

Adult Home Range Size And Juvenile Movements Of Gray Hawks In The Lower Rio Grande Valley, Texas, Usa, Michael T. Stewart, William S. Clark, Brian A. Millsap, Brent D. Bibles, Timothy Brush

Biology Faculty Publications and Presentations

We studied the natural history of Gray Hawks (Buteo plagiatus) in the Lower Rio Grande Valley of Texas. We used GPS-GSM telemetry to quantify dispersal time and distance, winter home range size of juveniles, and home range size of adults. Home ranges were calculated using the kernel Brownian bridge home range estimator. The median dispersal date for 14 juvenile Gray Hawks was 11 August and they traveled a median straight-line distance of 453 km. Mean winter home range sizes for 11 juveniles was 707 ha. For juveniles, female winter home ranges were larger than those of males, and …

Population Density And Reproductive Seasonality Of Tryonia Cheatumi (Gastropoda: Cochliopidae), The Phantom Tryonia, Kathryn E. Perez, Nina Noreika, Chad Norris, Marty Kelly, Melissa Lopez, Christina Ortega, Salma Ruiz Sandoval, Samantha Gonzalez, Weston Nowlin

Biology Faculty Publications and Presentations

We studied population density, population size, and reproductive seasonality of the Phantom Tryonia, Tryonia cheatumi (Pilsbry, 1935). This endangered freshwater snail is found only in the San Solomon Spring system, a cienega, or karst-based, arid-land freshwater spring system, in western Texas, USA. We sampled populations at seven locations in the system seasonally over a 2-yr period. San Solomon Spring, the system's largest spring and modified into a swimming pool, had the largest population of T. cheatumi, with an estimated 49 million individuals and a mean density as high as 23,626 ± 39,030 (individuals/m2 ± SD). There were seasonal differences …

Soil Nematode Trophic Group Composition And Influence On Growth Of Amaranthus Palmeri And Parthenium Hysterophorus, Orlando Garcia, Dana Garibaldi, Krissa Jhaveri, Jake Lanoue, Pushpa G. Soti

Biology Faculty Publications and Presentations

Weeds have a significant impact on agricultural systems. They not only cause a loss in crop yield by competing with them for resources, but they can also serve hosts for several pests and parasties such as plant parasitic nematodes casusing additional crop loss. The aim of this study was to analyze plant-nematode feedback in two major weeds, Amaranthus palmeri S Watson and Parthenium hysterophorus L. First, a field survey was conducted to determine the rhizosphere nematode trophic groups associated with these two plants in the summer of 2020 and 2021. Then a 6-week greenhouse study was conducted where the two …

Mechanistic Insight Into Functionally Different Human Islet Polypeptide (Hiapp) Amyloid: The Intrinsic Role Of The C-Terminal Structural Motifs, Dibakar Sarkar, Narayan Chandra Maity, Gourav Shome, Kyriakos Gabriel Varnava, Vijayalekshmi Sarojini, Subramanian Vivekanandan, Nirakar Sahoo, Sourav Kumar, Atin Kumar Mandal, Ranjit Biswas, Anirban Bhunia

Biology Faculty Publications and Presentations

Targeting amyloidosis requires high-resolution insight into the underlying mechanisms of amyloid aggregation. The sequence-specific intrinsic properties of a peptide or protein largely govern the amyloidogenic propensity. Thus, it is essential to delineate the structural motifs that define the subsequent downstream amyloidogenic cascade of events. Additionally, it is important to understand the role played by extrinsic factors, such as temperature or sample agitation, in modulating the overall energy barrier that prompts divergent nucleation events. Consequently, these changes can affect the fibrillation kinetics, resulting in structurally and functionally distinct amyloidogenic conformers associated with disease pathogenesis. Here, we have focused on human Islet …

Low Soil Nitrogen And Moisture Limit The Expansion Of The Invasive Grass, Megathyrsus Maximus (Guinea Grass) In Semi-Arid Soils, E. Penelope Holland, Vanessa Thomas, Pushpa G. Soti

Biology Faculty Publications and Presentations

The goal of this study was to predict the range expansion potential of an invasive forage grass, Guinea grass (Megathyrsus maximus). We collected rhizosphere soil samples of M. maximus and coexisting species from 150 different locations and analysed them for soil properties. We estimated the probability of M. maximus presence as a function of soil moisture, organic matter, pH, salinity, total N, and CN ratio using logistic regression. Presence of M. maximus was associated with higher soil moisture, higher organic matter, pH, and nitrogen, but lower salinity and CN ratio. Soil nitrogen and moisture …

Intracellular Hemin Is A Potent Inhibitor Of The Voltage-Gated Potassium Channel Kv10.1, Nirakar Sahoo, Kefan Yang, Alisa Bernert, Sandip M. Swain, Guido Gessner, Reinhard Kappl, Toni Kühl, Diana Imhof, Toshinori Hoshi, Roland Schönherr, Stefan H. Heinemann

Biology Faculty Publications and Presentations

Heme, an iron-protoporphyrin IX complex, is a cofactor bound to various hemoproteins and supports a broad range of functions, such as electron transfer, oxygen transport, signal transduction, and drug metabolism. In recent years, there has been a growing recognition of heme as a non-genomic modulator of ion channel functions. Here, we show that intracellular free heme and hemin modulate human ether à go-go (hEAG1, Kv10.1) voltage-gated potassium channels. Application of hemin to the intracellular side potently inhibits Kv10.1 channels with an IC50 of about 4 nM under ambient and 63 nM under reducing conditions in a weakly voltage-dependent manner, …