title: CD21 signaling via C3 regulates Purkinje cell protein 4 expression.
abstract: Complement receptor proteins CR2 (CD21) and CR1 (CD35) have been identified as components of the murine B cell co-receptor complex. Gene expression profiles between naïve WT, C3-/-, and CD21/35-/- B cells demonstrate enhanced expression of a Ca(2+)-modulating gene, Pcp4, in WT mice compared to the complement-deficient animals. Increased expression of Pcp4 is also coincident with B cell maturation into end stage phenotypes. Prolonged activation of B cells via cross-linking of the BCR (but not CR1/CR2 alone) leads to increased expression of Pcp4 and suppressed Ca(2+) release. In total these data demonstrate that the expression of Pcp4 in naïve resting mature B cells is dependent upon tonic stimulation from the CR1/CR2 proteins via a C3 ligand, and that antigen specific B cell activation can also elevate Pcp4 expression that is coincident with suppression of calcium-dependent responses.
authors.affiliation: Division of Cell Biology and Immunology, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
authors.forename: Amanda C
authors.initials: AC
authors.lastname: Jacobson
authors.forename: Janis J
authors.initials: JJ
authors.lastname: Weis
authors.forename: John H
authors.initials: JH
authors.lastname: Weis
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism / Q000502:physiology; D002454:Cell Differentiation / Q000235:genetics; D002478:Cells, Cultured; D003176:Complement C3 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D051562:Proto-Oncogene Proteins c-bcr / Q000378:metabolism / Q000502:physiology; D017463:Receptors, Complement 3b / Q000235:genetics / Q000378:metabolism; D017464:Receptors, Complement 3d / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D013154:Spleen / Q000378:metabolism
chemical_list: D003176:Complement C3; D003432:Cross-Linking Reagents; D009419:Nerve Tissue Proteins; C489091:Pcp4 protein, mouse; D017463:Receptors, Complement 3b; D017464:Receptors, Complement 3d; C496614:Bcr protein, mouse; D051562:Proto-Oncogene Proteins c-bcr