Abstract

cellular function of Host Cell Factor (HCF). Human HCF (also termed C1, VCAF, and CFF) is a highly conserved nuclear protein that was first discovered as a result of its association with the herpes simplex virus (HSV) transactivator VP16 during HSV infection. Aside from its involvement in human viral infection, HCF has an important role in uninfected cells and its activity has been conserved in all metazoan species tested, including D. melanogaster and C. elegans. HCF has unusual structural properties. It is synthesized as a large 2035 amino-acid-long protein that is processed through proteolytic cleavage. Cleavage is directed by and occurs within a 26 amino acid sequence that is repeated six times near the center of HCF. Cleavage at these HCF repeats results in a heterogeneous set of similarly sized amino and carboxy terminal HCF fragments that remain associated with each other. Recently, HCF has been shown to be involved in cell proliferation. In a temperature sensitive hamster kidney cell line, a single amino acid substitution in HCF causes the arrest of cell proliferation at the nonpermissive temperature. This temperature sensitive HCF is also defective for interaction with VP16 and the cellular DNA binding leucine zipper protein (LZIP)- a putative cellular effector protein of HCF. In this project, the structure of HCF and its cellular functions will be dissected, focusing on HCF maturation though HCF repeat directed proteolysis, its role in cell proliferation and its functional interaction with other cellular proteins. Areas to be investigated are: (i) determine whether the subcellular localization of HCF or the association of amino and carboxy terminal HCF polypeptides are regulated during the cell cycle, (ii) identify the mechanisms by which HCF is proteolytically processed, (iii) determine the structure and function of HCF subdomains, (iv) identify the role of HCF in cell proliferation, and (v) elucidate the structure and function of HCF in heterologous organisms.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM054598-04
Application #
6019169
Study Section
Molecular Biology Study Section (MBY)
Project Start
1996-08-01
Project End
2001-07-31
Budget Start
1999-08-01
Budget End
2001-07-31
Support Year
4
Fiscal Year
1999
Total Cost
Indirect Cost

  Institution

Name
Cold Spring Harbor Laboratory
Department
Type
DUNS #
065968786
City
Cold Spring Harbor
State
NY
Country
United States
Zip Code
11724

  Publications

Tyagi, Shweta; Chabes, Anna Lena; Wysocka, Joanna et al. (2007) E2F activation of S phase promoters via association with HCF-1 and the MLL family of histone H3K4 methyltransferases. Mol Cell 27:107-19
Julien, Eric; Herr, Winship (2004) A switch in mitotic histone H4 lysine 20 methylation status is linked to M phase defects upon loss of HCF-1. Mol Cell 14:713-25
Yokoyama, Akihiko; Wang, Zhong; Wysocka, Joanna et al. (2004) Leukemia proto-oncoprotein MLL forms a SET1-like histone methyltransferase complex with menin to regulate Hox gene expression. Mol Cell Biol 24:5639-49
Julien, Eric; Herr, Winship (2003) Proteolytic processing is necessary to separate and ensure proper cell growth and cytokinesis functions of HCF-1. EMBO J 22:2360-9
Wysocka, Joanna; Myers, Michael P; Laherty, Carol D et al. (2003) Human Sin3 deacetylase and trithorax-related Set1/Ash2 histone H3-K4 methyltransferase are tethered together selectively by the cell-proliferation factor HCF-1. Genes Dev 17:896-911
Reilly, Patrick T; Herr, Winship (2002) Spontaneous reversion of tsBN67 cell proliferation and cytokinesis defects in the absence of HCF-1 function. Exp Cell Res 277:119-30
Reilly, Patrick T; Wysocka, Joanna; Herr, Winship (2002) Inactivation of the retinoblastoma protein family can bypass the HCF-1 defect in tsBN67 cell proliferation and cytokinesis. Mol Cell Biol 22:6767-78
Wysocka, J; Reilly, P T; Herr, W (2001) Loss of HCF-1-chromatin association precedes temperature-induced growth arrest of tsBN67 cells. Mol Cell Biol 21:3820-9
Lee, S; Herr, W (2001) Stabilization but not the transcriptional activity of herpes simplex virus VP16-induced complexes is evolutionarily conserved among HCF family members. J Virol 75:12402-11
Wysocka, J; Liu, Y; Kobayashi, R et al. (2001) Developmental and cell-cycle regulation of Caenorhabditis elegans HCF phosphorylation. Biochemistry 40:5786-94

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