Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1997 Dec;17(12):7108-18.
doi: 10.1128/MCB.17.12.7108.

Concerted activity of host cell factor subregions in promoting stable VP16 complex assembly and preventing interference by the acidic activation domain

S LaBoissière  1 , S Walker, P O'Hare
Affiliations

Concerted activity of host cell factor subregions in promoting stable VP16 complex assembly and preventing interference by the acidic activation domain

S LaBoissière et al. Mol Cell Biol. 1997 Dec.

Abstract

In contrast to our understanding of the roles of Oct-1 and VP16 in VP16-mediated transcriptional activation, virtually nothing is known of the role of the second cellular component, termed host cell factor (HCF), or of its structure-function relationships. We show that the majority of the internal region of HCF, including the repeats involved in HCF cleavage, is dispensable for complex assembly with VP16 and Oct-1. The N-terminal domain of HCF (HCF.N) had only weak VP16 binding and complex promoting activity, while the C-terminal region (HCF.C) had no intrinsic activity. However, the C-terminal region strongly enhanced complex formation and reduced dissociation kinetics when linked to the N-terminal domain (HCF.NC). The potent activity of the HCF.NC fusion in complex assembly was recapitulated in vivo in yeast and mammalian cells. Moreover, HCF.N could promote increased complex formation when the acidic activation domain of VP16 was deleted. Restoration of the activation domain strongly inhibited complex formation with HCF.N, but the addition of the C-terminal domain of HCF restored strong stable complex formation with intact VP16. The results indicate that this C-terminal domain is critically required to alter the presentation of the acidic domain of VP16. Additional results are consistent with the interpretation that this alteration in acidic domain presentation for complex assembly also facilitates the activation function in VP16. The sequence of an HCF homolog from Caenorhabditis elegans shows it to be a natural HCF.NC construct, reinforcing the conclusions from our functional analysis.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. J Virol. 1990 Jun;64(6):2716-24 - PubMed
    1. EMBO J. 1988 Dec 20;7(13):4231-8 - PubMed
    1. Nucleic Acids Res. 1990 Dec 11;18(23):6871-80 - PubMed
    1. Cell. 1991 Feb 8;64(3):475-8 - PubMed
    1. Mol Cell Biol. 1991 Mar;11(3):1739-44 - PubMed

Publication types

MeSH terms

LinkOut - more resources