Membrane Protein Structure-Function Characterization
(Research Description PDF)
The Hu lab has broad interest in structural biochemistry of macromolecules important in biology and biomedicine with a focus on bio-metal utilization and homeostasis. By deploying multidisciplinary approaches, including those in structural biology (x-ray crystallography, cryo-EM, and NMR), biochemistry, biophysics, and cell biology, we aim to clarify the working mechanisms of macromolecules at atomic resolution. Three major ongoing projects are outlined below.
ZIP metal transporters. The Zrt-/Irt-like protein (ZIP) family members are ubiquitously expressed in nearly all the living organisms and play a central role in homeostasis of life-essential d-block metals (primarily Zn, Fe, and Mn). We strive to clarify the structural basis of (1) the alternating access transport mechanism, (2) substrate specificity and promiscuity, and (3) substratedependent endocytosis of eukaryotic ZIPs. Rationally engineering plant ZIPs to reduce heavy metal (particularly Cd) contamination in food is another ongoing project. Seeking ZIP-specific inhibitors/antibodies as cancer therapeutics is also under investigation (Figure 1).
Lar proteins. LarA from Lactobacillus plantarum (LarALP) is the founding member of the LarA racemase/epimerase family. The activity of LarALP relies on a newly-discovered Ni-pincer nucleotide (NPN) cofactor which is biosynthesized by three novel enzymes LarB, LarC and LarE in the lar operon. We have been collaborating with Dr. Robert P. Hausinger in MMG to (1) establish the structural basis of catalysis conducted by LarALP and LarA homologs broadly distributed in prokaryotes, and (2) clarify the process and the underlying mechanism of biosynthesis of the NPN cofactor (Figure 2).
PIPK lipid kinases. Phosphatidylinositol phosphate kinase (PIPK) family members produce the three types of PIP2, all of which are crucial signaling molecules involved in numerous biological processes. PIPKs are also potential drug targets for human diseases, including cancers, diabetes, inflammations, chronic pain, as well as viral infection (COVID-19 in particular). We aim to delineate the membrane sensing mechanism and the molecular basis of substrate promiscuity. We are also targeting the substrate binding site to develop non- ATP competitive inhibitors through collaboration with Dr. Xuefei Huang in Chemistry (Figure 3).
Area(s) of Interest
Zinc transporter mutations linked to Acrodermatitis enteropathica disrupt function and cause mistrafficking, Kuliyev, E., Zhang, C., Sui, D., and Hu, J., J. Biol. Chem. 2021 (in press).
Toward unzipping the ZIP metal transporters: structure, evolution, and implications on drug discovery against cancer, Hu, J., FEBS J. 2021 (in press; invited State-of-the-Art Review).
Molecular basis of zinc-dependent endocytosis of human ZIP4 transceptor, Zhang, C., Sui, D., Zhang, T. and Hu, J., Cell Rep. 2020, 31(4), 107582. PMID: 32348750.
Asymmetric functions of a binuclear metal center within the transport pathway of a human zinc transporter ZIP4, Zhang, T., Sui, D., Zhang, C., Cole, L. and Hu, J., The FASEB J. 2020, 34(1), 237-247. PMID: 31914589
Structural insights into lethal contractural syndrome type 3 (LCCS3) caused by a missense mutation of PIP5Kg, Zeng, X., Uyar, A., Sui, D., Donyapour, N., Wu, D., Dickson, A., and Hu, J.Biochem J. 2018, 475(14), 2257-2269.
Crystal structures of a ZIP zinc transporter reveal a binuclear metal center in the transport pathway, Zhang, T., Liu, J. Fellner, M., Zhang, C., Sui, D. and Hu, J., Sci. Adv. 2017, 3(8), e1700344.
Structural insights into the catalytic mechanism of LarE, a sacrificial sulfur insertase of the N-type ATP pyrophosphatase family, Fellner, M., Desguina, B., Hausinger, R.P., and Hu, J. Proc. Natl. Acad. Sci. USA 2017, 114(34): 9074-9079.
Structures and mechanisms of the non-heme Fe(II)- and 2-oxoglutarate-dependent ethylene-forming enzyme: substrate binding creates a twist, Martinez, S., Fellner, M., Herr, C.Q., Ritchie, A., Hu, J.†, and Hausinger, R.P.,JACS 2017, 139(34): 11980–11988.
B.S., 1999, Peking Univ.
Ph.D., 2004, Peking Univ.
Postdoctoral Research Assoc., 2005-07, Florida State Univ. and National High Magnetic Field Laboratory.
Postdoctoral Research Assoc., 2008-09, Yale Univ.
Associate Research Scientist, 2010-13, Yale Univ.