The N-terminus of COX-1 and its effect on cyclooxygenase-1 catalytic activity

Yibing Xu; Sean Phipps; Michael J. Turner; Daniel L. Simmons

doi:10.1016/S1673-8527(09)60030-8

Volume 37 Issue 2

Feb. 2010

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Article Navigation > Journal of Genetics and Genomics > 2010 > 37(2): 117-123

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The N-terminus of COX-1 and its effect on cyclooxygenase-1 catalytic activity

doi: 10.1016/S1673-8527(09)60030-8

Chemistry and Biochemistry Department, Brigham Young University, Provo, UT 84601, USA

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Corresponding author: E-mail address: yibing_xu@yahoo.com (Yibing Xu)
Received Date: 2009-10-26
Accepted Date: 2009-11-20
Rev Recd Date: 2009-11-13

Available Online: 2010-03-18

Publish Date: 2010-02-20

Abstract

Abstract

Cyclooxygenases are encoded by COX-1 and COX-2. They share over sixty percent sequence identity in human and are similar to each other in their crystallographic structures. One major difference in the primary structure of these two isozymes is the presence of eight amino acids in the amino-terminal region of COX-1 that are not present in COX-2. The function of this amino acid sequence is unknown. In this study, a human COX-1 mutant (Δ7aa) with this sequence removed was studied in parallel with COX-1. Signal peptide cleavage, N-linked glycosylation, protein expression, distribution and dimerization were not affected by the mutation. The mutant was enzymatically active and showed the same sensitivity toward aspirin. The KM for the enzyme remained the same as COX-1. However, the V_max of the COX-1 mutant decreased by 3.3-fold. We conclude that the COX-1 specific amino-terminal sequence has a subtle but detectable effect on COX-1 catalysis.
- COX-1,
- COX-2,
- dimerization,
- glycosylation,
- aspirin

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References(16)

References

[1]	Bachmair, A., Finley, D., Varshavsky, A. Science, 234 (1986),pp. 179-186
[2]	Gierse, J.K., McDonald, J.J., Hauser, S.D. et al. A single amino acid difference between cyclooxygenase-1 (COX-1) and −2 (COX-2) reverses the selectivity of COX-2 specific inhibitors J. Biol. Chem., 271 (1996),pp. 15810-15814
[3]	Guo, Q., Wang, L., Ruan, K. et al. Role of Val509 in time-dependent inhibition of human prostaglandin H synthase-2 cyclooxygenase activity by isoform-selective agents J. Biol. Chem., 271 (1996),pp. 19134-19139
[4]	Hynes, J., Hill, R., Papkovsky, D.B. The use of a fluorescence-based oxygen uptake assay in the analysis of cytotoxicity Toxicol. In Vitro, 20 (2006),pp. 785-792
[5]	Kurumbail, R., Stevens, A., Gierse, J. et al. Structural basis for selective inhibition of cyclooxygenase-2 by anti-inflammatory agents Nature, 384 (1996),pp. 644-648
[6]	Luong, C., Miller, A., Barnett, J. et al. Flexibility of the NSAID binding site in the structure of human cyclooxygenase-2 Nat. Struct. Biol., 3 (1996),pp. 927-933
[7]	Otto, J.C., Smith, W.L. Photolabeling of prostaglandin endoperoxide H synthase-1 with 3-trifluoro-3-(m-(125I)iodophenyl) diazirine as a probe of membrane association and the cyclooxygenase active site J. Biol. Chem., 271 (1996),pp. 9906-9910
[8]	Spencer, A.G., Thuresson, E., Otto, J.C. et al. The membrane binding domains of prostaglandin endoperoxide H synthases 1 and 2. Peptide mapping and mutational analysis J. Biol. Chem., 274 (1999),pp. 32936-32942
[9]	Santilli, F., Rocca, B., Cristofaro, R.D. et al. Platelet cyclooxygenase inhibition by low-dose aspirin is not reflected consistently by platelet function assays J. Am. Coll. Cardiol., 53 (2009),pp. 667-677
[10]	Simmons, D.L., Botting, R.M., Hla, T. Cyclooxygenase isozymes: the biology of prostaglandin synthesis and inhibition Pharmacol. Rev., 56 (2004),pp. 387-437
[11]	Smith, W.L., DeWitt, D.L. Prostaglandin endoperoxide H synthases-1 and −2 Adv. Immunol., 62 (1996),pp. 167-215
[12]	Wehbrink, D., Hässig, M., Ritter, N. et al. Immunohistochemical demonstration of cyclooxygenase-2 (COX-2) and prostaglandin receptors EP2 and FP expression in the bovine intercaruncular uterine wall around term Ani. Rep. Sci., 106 (2008),pp. 241-254
[13]	Wong, E., Bayly, C., Waterman, H.L. et al. Conversion of prostaglandin G/H synthase-1 into an enzyme sensitive to PGHS-2-selective inhibitors by a double His513 to Arg and Ile523 to Val mutation J. Biol. Chem., 272 (1997),pp. 9280-9286
[14]	Xu, Y., Chandrasekharan, N.V., Simmons, D.L. Screening large numbers of recombinant plasmids: modifications and additions to alkaline lysis for greater efficiency Prog. Nat. Sci., 16 (2006),pp. 1231-1233
[15]	Xu, Y., Oliverson, B.G., Simmons, D.L. Trifunctional inhibition of COX-2 by extracts of Lonicera japonica: direct inhibition, transcriptional and post-transcriptional down regulation J. Ethnopharmacol., 111 (2007),pp. 667-670
[16]	Yu, Y., Fan, J., Hui, Y. et al. J. Biol. Chem., 282 (2007),pp. 1498-1506