- Assistant Professor, Department of Food Science and Technology
The goal of Dr. Piepenbrink’s research program is to elucidate the molecular mechanisms by which bacteria interact with their surroundings; this includes host cells, abiotic surfaces, extracellular structures and, in particular, other bacteria. Dr. Piepenbrink’s group is approaching the basic question of how bacteria self-assemble into communities by applying the lenses of structural biology and biophysics to microbial surface structures.
These studies seek to explain the phenotypic differences between bacterial strains of similar genetic background; typically by comparing pathogenic bacteria to their commensal or environmental counterparts. The current focus is on type IV filaments, a class of extracellular appendages common to a wide range of bacteria, both Gram-positive and Gram-negative. To these ends, they pursue a variety of objectives: i) determining the high-resolution three-dimensional structures of the proteins and glycoproteins which make up extracellular assemblies, ii) using lower-resolution structural techniques in combination with molecular modeling to understand how subunits are assembled into extracellular superstructures, iii) identifying substrates for intermolecular interactions that underpin the adhesive activity of pili and other bacterial appendages and iv) elucidating the role of extracellular polymers, particularly protein fibers and polysaccharides, in promoting and stabilizing bacterial biofilms.
Richard K, Piepenbrink KH, Shirey KA, Gopalakrishnan A, Nallar S, Prantner DJ, Perkins DJ, Lai W, Vlk A, Toshchakov VY, Feng C, Fanaroff R, Medvedev AE, Blanco JCG, Vogel SN. A mouse model of human TLR4 D299G/T399I SNPs reveals mechanisms of altered LPS and pathogen responses. J Exp Med. 2021 Feb 1;218(2):e20200675. doi: 10.1084/jem.20200675. PMID: 33216117
Piepenbrink KH. DNA Uptake by Type IV Filaments. Front Mol Biosci. 2019 Feb 5;6:1. doi: 10.3389/fmolb.2019.00001. Review eCollection 2019. PMID: 30805346
Vila T, Kong EF, Ibrahim A, Piepenbrink KH, Shetty AC, McCracken C, Bruno V, Jabra-Rizk MA. Candida albicans quorum-sensing molecule farnesol modulates staphyloxanthin production and activates the thiol-based oxidative-stress response in Staphylococcus aureus. Virulence. 2019 Dec;10(1):625-642. doi: 10.1080/21505594.2019.1635418. PMID: 31280653
Ronish LA, Lillehoj E, Fields JK, Sundberg EJ, Piepenbrink KH. The structure of PilA from Acinetobacter baumannii AB5075 suggests a mechanism for functional specialization in Acinetobacter type IV pili. J Biol Chem. 2019 Jan 4;294(1):218-230. doi: 10.1074/jbc.RA118.005814. PMID: 30413536
Piepenbrink KH, Sundberg EJ. Motility and adhesion through type IV pili in Gram-positive bacteria. Biochem Soc Trans. 2016 Dec 15;44(6):1659-1666. doi: 10.1042/BST20160221. Review PMID: 27913675