Cytoplasmic and nuclear interaction between Rb family proteins and PAI-2: a physiological crosstalk in human corneal and conjunctival epithelial cells.
Extracellular plasminogen activator inhibitor type-2 (PAI-2) is a potent inhibitor of urokinase-type plasminogen activator (u-PA) and also acts as a multifunctional protein. However, the biological activity of intracellular PAI-2, as well as its intracellular targets, until now remain an enigma. Here, we show that pRb2/p130 and Rb1/p105, but not p107, interact with PAI-2 in both the cytoplasm and nucleus of normal primary human corneal and conjunctival epithelial cells. We provided the first in vivo evidence that a specific fragment of the PAI-2 promoter is bound simultaneously by pRb2/ p130, PAI-2, E2F5, histone deacetylase 1 (HDAC1), DNA methyltransferase 1 (DNMT1), and histone methyltransferase (SUV39H1), in normal primary human corneal epithelial cells, and by pRb2/p130, PAI-2, E2F5, HDAC1, and DNMT1, in normal primary human conjunctiva epithelial cells. Our results strongly indicate a physiological interaction between pRb family members and PAI-2, suggesting the hypothesis that pRb2/p130 and PAI-2 may cooperate in modulating PAI-2 gene expression by chromatin remodeling, in normal corneal and conjunctival cells.
Macaluso
M
M
Sbarro Institute for Cancer Research and Molecular Medicine, Center of Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA. macaluso@temple.edu
Montanari
M
M
Marshall
C M
CM
Gambone
A J
AJ
Tosi
G M
GM
Giordano
A
A
Massaro-Giordano
M
M
D002467:Cell Nucleus / Q000378:metabolism; D042002:Chromatin Assembly and Disassembly; D003228:Conjunctiva / Q000166:cytology / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D050700:E2F5 Transcription Factor / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism*; D019573:Epithelium, Corneal / Q000166:cytology / Q000378:metabolism*; D056284:Histone Deacetylase 1; D006655:Histone Deacetylases / Q000378:metabolism; D006801:Humans; D017396:Plasminogen Activator Inhibitor 2 / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D016160:Retinoblastoma Protein / Q000378:metabolism*; D050720:Retinoblastoma-Like Protein p107 / Q000378:metabolism*; D050717:Retinoblastoma-Like Protein p130 / Q000378:metabolism*
D050700:E2F5 Transcription Factor; C092558:E2F5 protein, human; D017396:Plasminogen Activator Inhibitor 2; D016160:Retinoblastoma Protein; D050720:Retinoblastoma-Like Protein p107; D050717:Retinoblastoma-Like Protein p130; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619380:DNMT1 protein, human; C110550:HDAC1 protein, human; D056284:Histone Deacetylase 1; D006655:Histone Deacetylases