Protein A est un gène codé par le symbole spa. Communément appelé aussi: Immunoglobulin G-binding IgG-binding Staphylococcal SpA; spa. Protein A a une masse de 56.44kDa et une longueur d'acide aminé de 516.
Nous proposons 8 Protein A protéines
Informations sur les Gènes et les Protéines
Résumé UniProt
Plays a role in the inhibition of the host innate and adaptive immune responses. Possesses five immunoglobulin-binding domains that capture both the fragment crystallizable region (Fc region) and the Fab region (part of Ig that identifies antigen) of immunoglobulins (PubMed:2938951, PubMed:4163007, PubMed:10805799). In turn, Staphylococcus aureus is protected from phagocytic killing via inhibition of Ig Fc region. In addition, the host elicited B-cell response is prevented due to a decrease of antibody-secreting cell proliferation that enter the bone marrow, thereby decreasing long-term antibody production. Inhibits osteogenesis by preventing osteoblast proliferation and expression of alkaline phosphatase, type I collagen, osteopontin and osteocalcin. Acts directly as a proinflammatory factor in the lung through its ability to bind and activate tumor necrosis factor alpha receptor 1/TNFRSF1A (By similarity).
Similitudes de séquence
Belongs to the immunoglobulin-binding protein SpA family.
Localisation cellulaire
Secreted > Cell wall. Secreted.
Cell wall anchoring is confered by the LPXTG motif and following sequences (PubMed:1638631). Anchored by sortase A (PubMed:10427003). SpA from strains A676 and V-I is secreted whereas SpA from Cowan 1 and 8325-4 is mostly attached to the cell wall (Probable). Newly synthesized protein is deposited at 2-4 foci/cell and eventually is distributed in a ring around the cell (PubMed:17416657).
Utilisation biotechnologique
Important immunodiagnostic reagent because of its ability to bind the Fab and Fc fragments of a wide range of mammalian immunoglobulins.
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