Biomaterial Database

The motheaten mutation rescues B cell signaling and development in CD45-deficient mice. 1997

G Pani, and K A Siminovitch, and C J Paige

Department of Immunology, University of Toronto, Toronto, Ontario, M4Y 1J3, Canada.

The cytosolic SHP-1 and transmembrane CD45 protein tyrosine phosphatases (PTP) play critical roles in regulating signal transduction via the B cell antigen receptor (BCR). These PTPs differ, however, in their effects on BCR function. For example, BCR-mediated mitogenesis is essentially ablated in mice lacking CD45 (CD45(-)), but is enhanced in SHP-1-deficient motheaten (me) and viable motheaten (mev) mice. To determine whether these PTPs act independently or coordinately in modulating the physiologic outcome of BCR engagement, we assessed B cell development and signaling in CD45-deficient mev (CD45-/SHP-1-) mice. Here we report that the CD45-/SHP-1-) cells undergo appropriate induction of protein kinase activity, mitogen-activated protein kinase activation, and proliferative responses after BCR aggregation. However, BCR-elicited increases in the tyrosine phosphorylation of several SHP-1-associated phosphoproteins, including CD19, were substantially enhanced in CD45-/SHP-1-, compared to wild-type and CD45- cells. In addition, we observed that the patterns of cell surface expression of mu, delta, and CD5, which distinguish the PTP-deficient from normal mice, are largely restored to normal levels in the double mutant animals. These findings indicate a critical role for the balance of SHP-1 and CD45 activities in determining the outcome of BCR stimulation and suggest that these PTPs act in a coordinate fashion to couple antigen receptor engagement to B cell activation and maturation.

UI	MeSH Term	Description	Entries
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D011947	Receptors, Antigen, B-Cell	IMMUNOGLOBULINS on the surface of B-LYMPHOCYTES. Their MESSENGER RNA contains an EXON with a membrane spanning sequence, producing immunoglobulins in the form of type I transmembrane proteins as opposed to secreted immunoglobulins (ANTIBODIES) which do not contain the membrane spanning segment.	Antigen Receptors, B-Cell,B-Cell Antigen Receptor,B-Cell Antigen Receptors,Surface Immunoglobulin,Immunoglobulins, Membrane-Bound,Immunoglobulins, Surface,Membrane Bound Immunoglobulin,Membrane-Bound Immunoglobulins,Receptors, Antigen, B Cell,Surface Immunoglobulins,Antigen Receptor, B-Cell,Antigen Receptors, B Cell,B Cell Antigen Receptor,B Cell Antigen Receptors,Bound Immunoglobulin, Membrane,Immunoglobulin, Membrane Bound,Immunoglobulin, Surface,Immunoglobulins, Membrane Bound,Membrane Bound Immunoglobulins,Receptor, B-Cell Antigen,Receptors, B-Cell Antigen
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001402	B-Lymphocytes	Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.	B-Cells, Lymphocyte,B-Lymphocyte,Bursa-Dependent Lymphocytes,B Cells, Lymphocyte,B Lymphocyte,B Lymphocytes,B-Cell, Lymphocyte,Bursa Dependent Lymphocytes,Bursa-Dependent Lymphocyte,Lymphocyte B-Cell,Lymphocyte B-Cells,Lymphocyte, Bursa-Dependent,Lymphocytes, Bursa-Dependent
D014443	Tyrosine	A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.	L-Tyrosine,Tyrosine, L-isomer,para-Tyrosine,L Tyrosine,Tyrosine, L isomer,para Tyrosine
D017027	Protein Tyrosine Phosphatases	An enzyme group that specifically dephosphorylates phosphotyrosyl residues in selected proteins. Together with PROTEIN-TYROSINE KINASE, it regulates tyrosine phosphorylation and dephosphorylation in cellular signal transduction and may play a role in cell growth control and carcinogenesis.	Phosphotyrosine Phosphatase,Protein-Tyrosine-Phosphatase,Tyrosyl Phosphoprotein Phosphatase,PTPase,Phosphotyrosyl Protein Phosphatase,Protein-Tyrosine Phosphatase,Phosphatase, Phosphotyrosine,Phosphatase, Phosphotyrosyl Protein,Phosphatase, Protein-Tyrosine,Phosphatase, Tyrosyl Phosphoprotein,Phosphatases, Protein Tyrosine,Phosphoprotein Phosphatase, Tyrosyl,Protein Phosphatase, Phosphotyrosyl,Protein Tyrosine Phosphatase,Tyrosine Phosphatases, Protein
D017493	Leukocyte Common Antigens	High-molecular weight glycoproteins uniquely expressed on the surface of LEUKOCYTES and their hemopoietic progenitors. They contain two FIBRONECTIN TYPE III DOMAINS and possess cytoplasmic protein tyrosine phosphatase activity, which plays a role in intracellular signaling from the CELL SURFACE RECEPTORS. Leukocyte common antigens occur as multiple isoforms that result from alternative mRNA splicing and differential usage of three exons.	Antigens, CD45,CD45 Antigens,CD45R Antigens,CD45RA Antigens,CD45RO Antigens,Protein Tyrosine Phosphatase, Receptor Type, C,2H4 Antigens,B220 Antigen,B220 Antigens,CD45 Antigen,CD45R0 Antigens,CD45RB Antigens,CD45RCAntigens,L-CA Antigens,Leukocyte Common Antigen,T200 Antigens,Antigen, B220,Antigen, CD45,Antigen, Leukocyte Common,Antigens, 2H4,Antigens, B220,Antigens, CD45R,Antigens, CD45R0,Antigens, CD45RA,Antigens, CD45RB,Antigens, CD45RO,Antigens, L-CA,Antigens, Leukocyte Common,Antigens, T200,L CA Antigens
D047908	Intracellular Signaling Peptides and Proteins	Proteins and peptides that are involved in SIGNAL TRANSDUCTION within the cell. Included here are peptides and proteins that regulate the activity of TRANSCRIPTION FACTORS and cellular processes in response to signals from CELL SURFACE RECEPTORS. Intracellular signaling peptide and proteins may be part of an enzymatic signaling cascade or act through binding to and modifying the action of other signaling factors.	Intracellular Signaling Peptides,Intracellular Signaling Proteins,Peptides, Intracellular Signaling,Proteins, Intracellular Signaling,Signaling Peptides, Intracellular,Signaling Proteins, Intracellular
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus
D053824	Protein Tyrosine Phosphatase, Non-Receptor Type 6	A Src-homology domain-containing protein tyrosine phosphatase found in the CYTOSOL of hematopoietic cells. It plays a role in signal transduction by dephosphorylating signaling proteins that are activated or inactivated by PROTEIN-TYROSINE KINASES.	Haematopoietic Cell Phosphatase,Hematopoietic Cell Phosphatase,Hematopoietic Cell-Specific Tyrosine Phosphatase SHP-1,Protein Tyrosine Phosphatase 1C,Protein Tyrosine Phosphatase, Nonreceptor Type 6,SHP-1 Phosphatase,SHP-1 Protein-Tyrosine Phosphatase,SHP-1 Tyrosine Phosphatase,SHP1 Phosphatase,SHP1 Protein Tyrosine Phosphatase,Hematopoietic Cell Specific Tyrosine Phosphatase SHP 1,Protein Tyrosine Phosphatase, Non Receptor Type 6,Protein-Tyrosine Phosphatase, SHP-1,SHP 1 Phosphatase,SHP 1 Protein Tyrosine Phosphatase,SHP 1 Tyrosine Phosphatase,Tyrosine Phosphatase, SHP-1