Biomaterial Database

Calcineurin B1 is essential for positive but not negative selection during thymocyte development. 2004

Joel R Neilson, and Monte M Winslow, and Eun Mi Hur, and Gerald R Crabtree

Department of Microbiology and Immunology, Beckman Center, Room B211, Stanford, CA 94305, USA.

During development, discrete cell fates often result from variation in the intensity of a particular signal. The mechanisms underlying these seemingly analog-to-digital switches are not understood. In developing T lymphocytes, low-intensity signals through the antigen receptor result in positive selection while more intense signals give rise to negative selection. By deleting the genetic locus encoding the regulatory B1 subunit of calcineurin specifically in thymocytes, we found an absolute requirement for calcineurin in positive selection. In contrast, calcineurin activity was dispensable in several models of negative selection. Unexpectedly, we found that removal of calcineurin activity from thymocytes results in inefficient ERK activation at the double-positive stage of thymocyte development, when selection occurs. These studies clarify the mechanism by which graded signals are converted to discrete outcomes in T cell development and further indicate that the developmental roles of calcineurin likely contribute to immunosuppression by calcineurin inhibitors.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D005260	Female		Females
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
D013950	Thymus Gland	A single, unpaired primary lymphoid organ situated in the MEDIASTINUM, extending superiorly into the neck to the lower edge of the THYROID GLAND and inferiorly to the fourth costal cartilage. It is necessary for normal development of immunologic function early in life. By puberty, it begins to involute and much of the tissue is replaced by fat.	Thymus,Gland, Thymus,Glands, Thymus,Thymus Glands
D016176	T-Lymphocyte Subsets	A classification of T-lymphocytes, especially into helper/inducer, suppressor/effector, and cytotoxic subsets, based on structurally or functionally different populations of cells.	T-Cell Subset,T-Cell Subsets,T-Lymphocyte Subset,Subset, T-Cell,Subset, T-Lymphocyte,Subsets, T-Cell,Subsets, T-Lymphocyte,T Cell Subset,T Cell Subsets,T Lymphocyte Subset,T Lymphocyte Subsets
D017353	Gene Deletion	A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.	Deletion, Gene,Deletions, Gene,Gene Deletions
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
D018448	Models, Immunological	Theoretical representations that simulate the behavior or activity of immune system, processes, or phenomena. They include the use of mathematical equations, computers, and other electrical equipment.	Immunological Models,Immunologic Model,Model, Immunologic,Immunologic Models,Immunological Model,Model, Immunological,Models, Immunologic
D019703	Calcineurin	A CALCIUM and CALMODULIN-dependent serine/threonine protein phosphatase that is composed of the calcineurin A catalytic subunit and the calcineurin B regulatory subunit. Calcineurin has been shown to dephosphorylate a number of phosphoproteins including HISTONES; MYOSIN LIGHT CHAIN; and the regulatory subunits of CAMP-DEPENDENT PROTEIN KINASES. It is involved in the regulation of signal transduction and is the target of an important class of immunophilin-immunosuppressive drug complexes.	Calcineurin A,Calcineurin B,Protein Phosphatase-2B,Protein Phosphatase 3,Protein Phosphatase 3 Catalytic Subunit,Protein Phosphatase 3 Regulatory Subunit,Phosphatase 3, Protein,Protein Phosphatase 2B
D020928	Mitogen-Activated Protein Kinases	A superfamily of PROTEIN SERINE-THREONINE KINASES that are activated by diverse stimuli via protein kinase cascades. They are the final components of the cascades, activated by phosphorylation by MITOGEN-ACTIVATED PROTEIN KINASE KINASES, which in turn are activated by mitogen-activated protein kinase kinase kinases (MAP KINASE KINASE KINASES).	Mitogen Activated Protein Kinase,Mitogen-Activated Protein Kinase,Kinase, Mitogen-Activated Protein,Kinases, Mitogen-Activated Protein,Mitogen Activated Protein Kinases,Protein Kinase, Mitogen-Activated,Protein Kinases, Mitogen-Activated