|
|
||||||||
CELLULAR METABOLISM
Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia
Submitted 23 February 2005 ; accepted in final form 24 March 2005
Hepatocyte growth factor activator inhibitor-1 (HAI-1) was initially identified as cognate inhibitor of matriptase, a membrane-bound serine protease. Paradoxically, HAI-1 is also required for matriptase activation, a process that requires sphingosine 1-phosphate (S1P)-mediated translocation of the protease to cell-cell junctions in human mammary epithelial cells. In the present study, we further explored how HAI-1 regulates this protease. First, we observed that after S1P treatment HAI-1 was cotranslocated with matriptase to cell-cell junctions and that the cellular ratio of HAI-1 to matriptase was maintained during this process. However, when this ratio was changed by cell treatment with HAI-1 small interfering RNA or anti-HAI-1 MAb M19, spontaneous activation of matriptase occurred in the absence of S1P-induced translocation; S1P-induced matriptase activation was also enhanced. These results support a role for HAI-1 in protection of cell from uncontrolled matriptase activation. We next expressed matriptase, either alone or with HAI-1 in breast cancer cells that do not endogenously express either protein. A defect in matriptase trafficking to the cell surface occurred if wild-type matriptase was expressed in the absence of HAI-1; this defect appeared to result from matriptase toxicity to cells. Coexpression with matriptase of wild-type HAI-1, but not HAI-1 mutants altered in its Kunitz domain 1, corrected the trafficking defect. In contrast, catalytically defective matriptase mutants were normal in their trafficking in the absence of HAI-1. These results are also consistent with a role for HAI-1 to prevent inappropriate matriptase proteolytic activity during its protein synthesis and trafficking. Taken together, these results support multiple roles for HAI-1 to regulate matriptase, including its proper expression, intracellular trafficking, activation, and inhibition.
protease-activated receptor-2; hepatocyte growth factor; urokinase; sphingosine 1-phosphate; Kunitz domain
This article has been cited by other articles:
![]() |
I-C. Tseng, F.-P. Chou, S.-F. Su, M. Oberst, N. Madayiputhiya, M.-S. Lee, J.-K. Wang, D. E. Sloane, M. Johnson, and C.-Y. Lin Purification from human milk of matriptase complexes with secreted serpins: mechanism for inhibition of matriptase other than HAI-1 Am J Physiol Cell Physiol, August 1, 2008; 295(2): C423 - C431. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Kojima, S. Tsuzuki, T. Fushiki, and K. Inouye Roles of Functional and Structural Domains of Hepatocyte Growth Factor Activator Inhibitor Type 1 in the Inhibition of Matriptase J. Biol. Chem., February 1, 2008; 283(5): 2478 - 2487. [Abstract] [Full Text] [PDF] |
||||
![]() |
M.-S. Lee, I-C. Tseng, Y. Wang, K.-i. Kiyomiya, M. D. Johnson, R. B. Dickson, and C.-Y. Lin Autoactivation of matriptase in vitro: requirement for biomembrane and LDL receptor domain Am J Physiol Cell Physiol, July 1, 2007; 293(1): C95 - C105. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. S. Bhatt, A. Welm, C. J. Farady, M. Vasquez, K. Wilson, and C. S. Craik Coordinate expression and functional profiling identify an extracellular proteolytic signaling pathway PNAS, April 3, 2007; 104(14): 5771 - 5776. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Generali, S. B. Fox, A. Berruti, J. W. Moore, M. P. Brizzi, N. Patel, G. Allevi, S. Bonardi, S. Aguggini, A. Bersiga, et al. Regulation of Hepatocyte Growth Factor Activator Inhibitor 2 by Hypoxia in Breast Cancer Clin. Cancer Res., January 15, 2007; 13(2): 550 - 558. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Mori, G. Ishikawa, S.-S. Luo, T. Mishima, T. Goto, J. M. Robinson, S. Matsubara, T. Takeshita, H. Kataoka, and T. Takizawa The Cytotrophoblast Layer of Human Chorionic Villi Becomes Thinner but Maintains Its Structural Integrity During Gestation Biol Reprod, January 1, 2007; 76(1): 164 - 172. [Abstract] [Full Text] [PDF] |
||||
![]() |
K.-i. Kiyomiya, M.-S. Lee, I-C. Tseng, H. Zuo, R. J. Barndt, M. D. Johnson, R. B. Dickson, and C.-Y. Lin Matriptase activation and shedding with HAI-1 is induced by steroid sex hormones in human prostate cancer cells, but not in breast cancer cells Am J Physiol Cell Physiol, July 1, 2006; 291(1): C40 - C49. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |