Michael Kwofie

3rd Year Medical Student

Department: School of Medicine

Graduate Program: Genetics

Advisor: Dr. Jacek Skowronski

Abstract:

Title:  Dissecting the interaction between HIV-1 Nef and the DOCK2-ELMO1-Rac complex

Recent work in our lab showed that the lentiviral protein Nef specifically associates with the DOCK2-ELMO1-Rac complex to activate Rac and inhibit T cell chemotaxis. DOCK2, a hematopoietic-cell-specific protein, and ELMO1 serve as a bipartite guanine nucleotide exchange factor (GEF) for the Rho-family GTPase Rac, exchanging GDP for GTP. My goal is to characterize the interaction between Nef and the DOCK2-ELMO1-Rac complex. My attempt to map Nef target sites on the individual components of the complex by truncating DOCK2 and ELMO1 have not be conclusive. I am currently testing the effect of point mutations that disrupt DOCK2-ELMO1-Rac complex formation on the ability of Nef to form a tetrameric Nef-DOCK2-ELMO1-Rac complex. The protocol involves transient expression in HEK 293T cells followed by the sequential precipitation of Nef and a second component of the complex. Results obtained thus far indicate that Nef may modulate the function of the DOCK2-ELMO1-Rac complex by stabilizing Rac in the context of its GEF, DOCK2-ELMO1, or recruiting Rac to a complex of DOCK2 and ELMO1.

Publications:
(MSTP-supported publications indicated with an *)

*Suzuki T, Kwofie MA, Lennarz WJ. (2003). Ngly 1, a mouse gene encoding a deglycosylating enzyme implicated in proteasomal degradation: expression, genomic organization, and chromosomal mapping. Biochem Biophys Res Commun. 304:326-32.

*Suzuki T, Park H, Kwofie MA, Lennarz WJ. (2001). Rad23 provides a link between the Png1 deglycosylating nzyme and the 26 S proteasome in yeast. J Biol Chem. 276:21601-7.