The mouse T cell receptor gamma genes

Biochemistry;Molecular Biology

Vernooij, Bernardus Theodorus Maria ; Hood, Leroy E.

University:California Institute of Technology

Department:Biology

关键词: Biochemistry;    Molecular Biology;   

Others  :  https://thesis.library.caltech.edu/6682/1/Vernooij_btm_1992.pdf

美国|英语

来源: Caltech THESIS

【 摘 要 】

Murine T cells express either of 2 antigen receptors ontheir surface:αβ or γδ T cell receptors. The γδ T cellpopulation contains subsets which show tissue specificlocalization, invariant T cell receptors and/or specificityfor stress antigens. This makes these T cells unlike αβ Tcells.

This thesis describes the genomic organization of the entire mouse T cell receptor gamma locus. It contains 4 clusters of gene segments, each with a C, a J and 1 to 4 V gene segments. Compared to other T cell receptor andimmunoglobulin loci, this is an unusual organization. TheCγ2 cluster is in an orientation that is opposite to that ofall other clusters.

Two new γ enhancer-like elements were identified in thelocus. Also shown is that the hinge region of Cγ4 is encodedby at least 2 exons. This is similar to the geneorganization of the human Cγ2 gene segment, and differentfrom the other mouse and human Cγ gene segments.Sequence comparison of the T cell receptor γ gene segmentsof various mammals reveals structural conservation duringevolution. The C region is most conserved, except in thehinge region. This subdomain is variable in length and insequence. The extracellular domain is well conserved andcontains amino acid residues which are also conserved in theother T cell receptor and immunoglobulin proteins.

The Vγ gene segments are less well conserved, but severalamino acid residues are found which are (nearly) invariant.During evolution, the 2 studied mammals each appear to havelost certain V gene segments relative to a hypotheticalancestor.