title: The N-terminal ectodomain of Ninjurin1 liberated by MMP9 has chemotactic activity.
abstract: Ninjurin1 is known as an adhesion molecule promoting leukocyte trafficking under inflammatory conditions. However, the posttranslational modifications of Ninjurin1 are poorly understood. Herein, we defined the proteolytic cleavage of Ninjurin1 and its functions. HEK293T cells overexpressing the C- or N-terminus tagging mouse Ninjurin1 plasmid produced additional cleaved forms of Ninjurin1 in the lysates or conditioned media (CM). Two custom-made anti-Ninjurin1 antibodies, Ab(1-15) or Ab(139-152), specific to the N- or C-terminal regions of Ninjurin1 revealed the presence of its shedding fragments in the mouse liver and kidney lysates. Furthermore, Matrix Metalloproteinase (MMP) 9 was responsible for Ninjurin1 cleavage between Leu(56) and Leu(57). Interestingly, the soluble N-terminal Ninjurin1 fragment has structural similarity with well-known chemokines. Indeed, the CM from HEK293T cells overexpressing the GFP-mNinj1 plasmid was able to attract Raw264.7 cells in trans-well assay. Collectively, we suggest that the N-terminal ectodomain of mouse Ninjurin1, which may act as a chemoattractant, is cleaved by MMP9.
authors.affiliation: NeuroVascular Coordination Research Center, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Bum Ju
authors.initials: BJ
authors.lastname: Ahn
authors.forename: Hoang
authors.initials: H
authors.lastname: Le
authors.forename: Min Wook
authors.initials: MW
authors.lastname: Shin
authors.forename: Sung-Jin
authors.initials: SJ
authors.lastname: Bae
authors.forename: Eun Ji
authors.initials: EJ
authors.lastname: Lee
authors.forename: Hee-Jun
authors.initials: HJ
authors.lastname: Wee
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Cha
authors.forename: Ji-Hyeon
authors.initials: JH
authors.lastname: Park
authors.forename: Hye Shin
authors.initials: HS
authors.lastname: Lee
authors.forename: Hyo-Jong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Hyunsook
authors.initials: H
authors.lastname: Jung
authors.forename: Zee-Yong
authors.initials: ZY
authors.lastname: Park
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Park
authors.forename: Byung Woo
authors.initials: BW
authors.lastname: Han
authors.forename: Ji Hae
authors.initials: JH
authors.lastname: Seo
authors.forename: Eng H
authors.initials: EH
authors.lastname: Lo
authors.forename: Kyu-Won
authors.initials: KW
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015816:Cell Adhesion Molecules, Neuronal / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018925:Chemokines / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002630:Chemotactic Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007930:Leucine / Q000737:chemistry; D008099:Liver / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000737:chemistry*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D018925:Chemokines; D002630:Chemotactic Factors; D009414:Nerve Growth Factors; C484439:Ninj1 protein, mouse; D020780:Matrix Metalloproteinase 9; D007930:Leucine