title: PAP I interacts with itself, PAP II, PAP III, and lithostathine/regIalpha.
abstract: PAP I, PAP II, PAP III, and lithostathine/regIalpha are members of a multigenic family of proteins expressed in several tissues. PAP I was shown to be antiapoptotic, mitogenic, and anti-inflammatory and can promote cell adhesion to the extracellular matrix. Lithostathine/regIalpha can be mitogenic. Because polymerization might regulate activity, we examined the ability of rat PAP I to interact with itself (homodimerization), PAP II, PAP III, and lithostathine/regIalpha (heterodimerization) by the yeast two-hybrid system, affinity experiments, and crosslinking. PAP I interacted significantly with all members of the PAP protein family, homodimerization showing the strongest interaction as judged by the beta-galactosidase test. This was confirmed by showing specific affinity between a MBP-rPAP I fusion protein and the native rPAP I. Finally, crosslinking experiments showed that rPAP I formed dimers in solution. These findings should be taken into account in functional studies involving PAP I and PAP-related proteins.
authors.affiliation: Laboratoire de Recherche de Physiologie et Pathologie Digestives, INSERM U.315, Marseille, France.
authors.forename: H
authors.initials: H
authors.lastname: Bödeker
authors.forename: V
authors.initials: V
authors.lastname: Keim
authors.forename: F
authors.initials: F
authors.lastname: Fiedler
authors.forename: J C
authors.initials: JC
authors.lastname: Dagorn
authors.forename: J L
authors.initials: JL
authors.lastname: Iovanna
mesh_terms: D000209:Acute-Phase Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000951:Antigens, Neoplasm; D001483:Base Sequence; D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003432:Cross-Linking Reagents; D017931:DNA Primers / Q000235:genetics; D019281:Dimerization; D066298:In Vitro Techniques; D037181:Lectins, C-Type; D051847:Lithostathine; D009419:Nerve Tissue Proteins; D000073718:Pancreatitis-Associated Proteins; D020836:Protein Structure, Quaternary; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D000209:Acute-Phase Proteins; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins; D003432:Cross-Linking Reagents; D017931:DNA Primers; D037181:Lectins, C-Type; D051847:Lithostathine; D009419:Nerve Tissue Proteins; D000073718:Pancreatitis-Associated Proteins; D011993:Recombinant Fusion Proteins; C497616:Reg1a protein, rat