title: Identification of protein-protein interactions of human HtrA1.
abstract: The human heat shock protein HtrA1, a member of the HtrA family of serine proteases, is a evolutionarily highly conserved factor which displays a widespread pattern of expression. The yeast two-hybrid technique was employed to identify new cellular proteins physically interacting with HtrA1, and thus potential targets of this serine protease. An enzymatically inactive HtrA1 point mutant, HtrA1-S328A, was generated and used as bait in a yeast two-hybrid system. Fifty-two plasmids were isolated from primary positive yeast clones. Subsequent sequencing and BLAST analysis revealed cDNAs encoding for 13 different proteins. These putative binding partners of HtrA1 appeared to be a) components of extracellular matrix; b) factors related to signal pathways, and c) unknown proteins. Among the 13 positive clones identified and reported here, it is worth of note that the interaction of HtrA1 with tubulin and collagen (extracellular matrix proteins) and with tuberin (cytoplasmic protein) is confirmed by other studies, and this further supports previous findings in which HtrA1 can be found active as an intracytoplasmic protein or as secreted protein as well.
authors.affiliation: Department of Biochemistry, Section of Pathology, Second University of Naples, Naples, Italy.
authors.forename: Mara
authors.initials: M
authors.lastname: Campioni
authors.forename: Anna
authors.initials: A
authors.lastname: Severino
authors.forename: Lucrezia
authors.initials: L
authors.lastname: Manente
authors.forename: Antonio
authors.initials: A
authors.lastname: De Luca
authors.forename: Raffaele
authors.initials: R
authors.lastname: La Porta
authors.forename: Antonio
authors.initials: A
authors.lastname: Vitiello
authors.forename: Paola
authors.initials: P
authors.lastname: Fiore
authors.forename: Stefano
authors.initials: S
authors.lastname: Toldo
authors.forename: Enrico P
authors.initials: EP
authors.lastname: Spugnini
authors.forename: Marco G
authors.initials: MG
authors.lastname: Paggi
authors.forename: Alfonso
authors.initials: A
authors.lastname: Baldi
mesh_terms: D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D000074289:High-Temperature Requirement A Serine Peptidase 1; D006801:Humans; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D000074289:High-Temperature Requirement A Serine Peptidase 1; C474012:HTRA1 protein, human; D012697:Serine Endopeptidases