TARPP, a novel protein that accompanies TCR gene rearrangement and thymocyte education.
Studies on thymic T cell development have usually concentrated on cell surface molecules. However, intracellular proteins expressed only in thymocytes have never been described. Here we report the discovery of a novel thymocyte-specific protein, named TARPP, which represents a high molecular mass ( approximately 100 kDa) variant of the previously identified protein ARPP-21 ( approximately 21 kDa). TARPP is a cytosolic protein that is expressed at high levels in immature thymocytes. It appears concomitant with the commitment to T cell lineage, and its expression is switched off as a consequence of TCR engagement during positive selection. Such an expression pattern, correlating with the rearrangement of the TCR genes and thymocyte education, suggests a role for TARPP during this important phase of thymocyte development.
Kisielow
J
J
Basel Institute for Immunology, Basel, Switzerland. jan.kisielow@bii.ch
Nairn
A C
AC
Karjalainen
K
K
D000375:Aging / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D001483:Base Sequence; D017252:CD3 Complex / Q000378:metabolism; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D003001:Cloning, Molecular; D015536:Down-Regulation; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D015329:Gene Rearrangement, T-Lymphocyte / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D054645:Protein Phosphatase 1; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013950:Thymus Gland / Q000166:cytology* / Q000196:embryology / Q000276:immunology / Q000378:metabolism*
D000906:Antibodies; D017252:CD3 Complex; D010750:Phosphoproteins; C424983:Ppp1r1c protein, mouse; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D054645:Protein Phosphatase 1