Wesley I. Sundquist
Professor and Co-Chair of Biochemistry
B.A. Carleton College
Ph.D. Massachusetts Institute of Technology
Wes Sundquist's Lab Page
Wes Sundquist's PubMed Literature Search
Research
We are interested in the molecular and structural biology of retroviruses, with particular emphasis on the Human Immunodeficiency Virus (HIV). Projects in the laboratory focus on understanding the architecture and assembly of the viral particle, the mechanisms of intrinsic host cell defenses, and the process of virus budding. Our approaches include NMR, EM, and crystallographic studies of viral complexes, biochemical analyses of the interactions between viral components and their cellular partners, and genetic analyses of viral protein functions.
The Human ESCRT Pathway. We (and others) have shown that the human cellular ESCRT pathway mediates the release of HIV from infected cells. This pathway normally functions to create vesicles that bud into a late endosomal compartment called the multivesicular body (MVB). The HIV Gag protein usurps this pathway by binding directly to ESCRT proteins, and thereby redirects the cellular machinery to the plasma membrane to facilitate virus budding. Our current focus is to understand precisely how the ESCRT pathway functions in HIV budding, and in a series of cellular processes, including MVB biogenesis, cytokinesis, and mitosis.
ESCRT Structural Biology. The human ESCRT pathway has more than 30 proteins, including at least two that bind HIV proteins. In collaboration with Chris Hill's laboratory, we are attempting to define the structural biology of this important pathway. We have completed structures of more than 12 proteins and complexes involved in HIV budding and are currently screening other candidate proteins and complexes for suitability in NMR and crystallographic studies. In addition to revealing structures of ESCRT components, these studies help generate testable hypotheses for pathway functions.
HIV-1 Disassembly and Restriction. The cone-shaped inner capsid of the mature infectious HIV-1 virus is organized by the viral CA protein. Upon infection, the capsid cone disassembles to release the viral replication particle into the cytoplasm of the newly infected cell. Our previous NMR, crystallographic, and EM studies have revealed the structure of the CA protein and explained how it can form a conical capsid. We are now studying how the HIV-1 capsid disassembles when the virus enters a new cell and how the capsid is recognized and destroyed by intrinsic cellular defense mechanisms.
Related research in the laboratory is aimed at reconstituting other aspects of HIV-1 viral assembly and disassembly in vitro, determining the structures of relevant multiprotein viral complexes, and identifying new interactions between HIV and cellular factors.
Above: Immature HIV particles arrest late in the budding process when cells lack TSG101. Bel0w: comparison of an authentic HIV particle (left), and a “synthetic” HIV capsid assembled in vitro.
References
1. Bajorek M, Schubert HL, McCullough J, Langelier C, Eckert DM, Stubblefield W-MB, Uter NT, Hill CP, Sundquist WI (2009) Structural basis for ESCRT-III protein autoinhibition. Nature Struct Mol Biol 16:754-762
2. Kieffer C, Skalicky JJ, Morita E, De Dominico I, Ward DM, Kaplan J, Sundquist WI (2008) Two distinct modes of ESCRT-III recognition are required for VPS4 functions in lysosomal protein targeting and HIV-1 budding. Dev Cell 15:62-73
3. McCullough J, Fisher RD, Whitby FG, Sundquist WI, Hill CP (2008) ALIX-CHMP4 interactions in the human ESCRT pathway. Proc. Natl. Acad. Sci. 105:7687-7691
4. Zhai Q, Fisher RD, Chung HY, Myszka DG, Sundquist WI, Hill CP (2008) Structural and functional studies of ALIX/AIP1 in complex with the YPXnL late domains from HIV-1 p6Gag and EIAV p9Gag. Nature Struct. Mol. Biol. 15:43-49
5. Morita E, Sandrin V, Chung HY, Morham SG, Gygi SP, Rodesch CK, Sundquist WI (2007) Human ESCRT and ALIX proteins interact with proteins of the midbody and function in cytokinesis. EMBO J. 26:4215-4217
6. Stuchell-Brereton MD, Skalicky JJ, Kieffer C, Karren MA, Ghaffarian S, Sundquist WI (2007) ESCRT-III recognition by VPS4 ATPases. Nature 449:740-744
7. Morita E, Sandrin V, Alam SL, Eckert DM, Gygi SP, Sundquist WI (2007) Identification of human MVB12 proteins as ESCRT-I subunits that function in HIV Budding. Cell Host Microbe 2:41-53
8. Fisher RD, Chung H-Y, Zhai Q, Robinson H, Sundquist WI, Hill CP (2007) Structural and bochemical studies of ALIX/AIP1 and its role in retroviral budding. Cell 128:841
9. Alam SL, Langelier C, Whitby FG, Koirala S, Robinson H, Hill CP, Sundquist WI (2006) Structural basis for ubiquitin recognition by the human EAP45/ESCRT-II GLUE domain. Nature Struct. Mol. Biol. 13:1029-1030
10. Scott A, Chung H-Y, Gonciarz-Swiatek M, Hill GC, Whitby FG, Gaspar J, Holton JM, Viswanathan R, Ghaffarian S, Hill CP, Sundquist WI (2005) Structural and mechanistic studies of human VPS4B. EMBO J. 24:3658-69
11. Scott A, Gaspar J, Stuchell M, Alam SL, Skalicky JJ, Sundquist WI (2005) Structure and ESCRT-III protein interactions of the MIT domain of VPS4A. Proc. Natl. Acad. Sci. USA 192:13,813-18
12. Morita E, Sundquist WI (2004) Retrovirus budding. Annu. Rev. Cell Dev. Biol., 20:395-425
13. von Schwedler U, Stuchell M, Müller B, Ward D, Chung H-Y, Morita E, Wang H, Davis T, He GP, Cimbora DM, Scott A, Kräusslich H-G, Kaplan J, Morham SG, Sundquist WI (2003) The protein network of HIV budding. Cell 114:701-13
14. Pornillos OW, Alam S, Davis DR, Sundquist WI (2002) Structure of the Tsg101 UEV domain in complex with a HIV-1 PTAP "late domain" peptide. Nature Struct. Biol. 9:812-817
15. Garrus JE, von Schwedler UK, Pornillos O, Morham SG, Zavitz KH, Wang HE, Wettstein DA, Stray KM, Cöté M, Rich RL, Myszka DG, Sundquist WI (2001) Tsg101 and the Vacuolar Protein Sorting Pathway are Essential for HIV-1 Budding. Cell 107: 55-65
16. Li S, Hill CP, Sundquist WI, Finch JT (2000) Image Reconstructions of helical assemblies of the HIV-1 CA protein. Nature 407:409-413
17. Ganser BK, Li S, Klishko VY, Finch JT, Sundquist WI (1999) Assembly and analysis of conical models for the HIV-1 core. Science 283:80-83
18. von Schwedler UK, Stemmler TL, Klishko VY, Li S, Albertine KH, Davis DR, Sundquist WI (1998) Proteolytic refolding of the HIV-1 capsid protein amino-terminus facilitates viral core assembly. EMBO Journal 17:1555-1568
19. Gamble TR, Yoo S, Vajdos FF, von Schwedler UK, Worthylake DK, Wang H, McCutcheon JP, Sundquist WI, Hill CP (1997) Structure of the carboxyl-terminal dimerization domain of the HIV-1 capsid protein. Science 278: 849-853
20. Gamble TR, Vajdos FF, Yoo S, Worthylake DK, Houseweart M, Sundquist WI, Hill CP (1996) Crystal structure of human cyclophilin A bound to the amino-terminal domain of HIV-1 capsid. Cell 87:1285-1294
Updated 8/15/2010
