@article{whitehurst_willis_sinodis_hernandez_brown_2006, title={Single and multiple deletions in the transmembrane domain of the Sindbis virus E2 glycoprotein identify a region critical for normal virus growth}, volume={347}, ISSN={["0042-6822"]}, DOI={10.1016/j.virol.2005.11.029}, abstractNote={Sindbis virus is composed of two nested T = 4 icosahedral protein shells containing 240 copies each of three structural proteins: E1, E2, and Capsid in a 1:1:1 stoichiometric ratio. E2 is a 423 amino acid glycoprotein with a membrane spanning domain 26 amino acids in length and a 33 amino acid cytoplasmic endodomain. The interaction of the endodomain with the nucleocapsid is an essential step in virus maturation and directs the formation of the outer protein shell as envelopment occurs. A previous study had determined that deletions in the transmembrane domain could affect virus assembly and infectivity (Hernandez et al., 2003. J. Virol. 77 (23), 12710-12719). Unexpectedly, a single deletion mutant (from 26 to 25 amino acids) resulted in a 1000-fold decrease in infectious virus production while another deletion of eight amino acids had no affect on infectious virus production. To further investigate the importance of these mutants, other single deletion mutants and another eight amino acid deletion mutant were constructed. We found that deletions located closer to the cytoplasmic (inner leaflet) of the membrane bilayer had a more detrimental effect on virus assembly and infectivity than those located closer to the luminal (outer leaflet) of the membrane bilayer. We also found that selective pressure can restore single amino acid deletions in the transmembrane domain but not necessarily to the wild type sequence. The partial restoration of an eight amino acid deletion (from 18 to 22 amino acids) also partially restored infectious virus production. The amount of infectious virus produced by this revertant was equivalent to that produced for the four amino acid deletion produced by site directed mutagenesis. These results suggest that the position of the deletion and the length of the C terminal region of the E2 transmembrane domain is vital for normal virus production. Deletion mutants resulting in decreased infectivity produce particles that appear to be processed and transported correctly suggesting a role involved in virus entry.}, number={1}, journal={VIROLOGY}, author={Whitehurst, CB and Willis, JH and Sinodis, CN and Hernandez, R and Brown, DT}, year={2006}, month={Mar}, pages={199–207} }
 @article{hernandez_ferreira_sinodis_litton_brown_2005, title={Single amino acid insertions at the junction of the Sindbis virus e2 transmembrane domain and endodomain disrupt virus envelopment and alter infectivity}, volume={79}, DOI={10.1128/JVI.79.7682-7697.2005}, number={12}, journal={Journal of Virology}, author={Hernandez, R. and Ferreira, D. and Sinodis, C. and Litton, K. and Brown, D. T.}, year={2005}, pages={7682–7697} }
 @article{hernandez_sinodis_horton_ferreira_yang_brown_2003, title={Deletions in the transmembrane domain of a Sindbis virus glycoprotein alter virus infectivity, stability, and host range}, volume={77}, ISSN={["0022-538X"]}, DOI={10.1128/JVI.77.23.12710-12719.2003}, abstractNote={The alphaviruses are composed of two icosahedral protein shells, one nested within the other. A membrane bilayer derived from the host cell is sandwiched between the protein shells. The protein shells are attached to one another by protein domains which extend one of the proteins of the outer shell through the membrane bilayer to attach to the inner shell. We have examined the interaction of the membrane-spanning domain of one of the membrane glycoproteins with the membrane bilayer and with other virus proteins in an attempt to understand the role this domain plays in virus assembly and function. Through incremental deletions, we have reduced the length of a virus membrane protein transmembrane domain from its normal 26 amino acids to 8 amino acids. We examined the effect of these deletions on the assembly and function of virus particles. We found that progressive truncations in the transmembrane domain profoundly affected production of infectious virus in a cyclic fashion. We also found that membrane composition effects protein-protein and protein-membrane interactions during virus assembly.}, number={23}, journal={JOURNAL OF VIROLOGY}, author={Hernandez, R and Sinodis, C and Horton, M and Ferreira, D and Yang, CN and Brown, DT}, year={2003}, month={Dec}, pages={12710–12719} }