J Michael Sauder - Identification of a novel pre-TCR isoform in which the accessibility of the TCR beta subunit is determined by occupancy of the 'missing' V domain of pre-T alpha

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      Publication Details (including relevant citation   information):

      Int Immunol (2000) 12: 1579-1591.

      Berger MA, Carleton M, Rhodes M, Sauder JM, Trop S, Dunbrack RL,   Hugo P, Wiest DL

      Abstract:

      We have identified a novel pre-TCR isoform that is structurally   distinct  from conventional pre-TCR complexes and whose TCR   beta chains are  inaccessible to anti-TCR beta antibodies.   We term this pre-TCR isoform  the MB (masked beta)-pre-TCR.   Pre-T alpha (pT alpha) subunits of  MB-pre-TCR complexes   have a larger apparent mol. wt due to extensive    modification with O:-linked carbohydrates; however, preventing   addition  of O-glycans does not restore antibody recognition   of the TCR beta  subunits of MB-pre-TCR complexes.   Importantly, accessibility of TCR beta  chains in MB-pre-TCR   complexes is restored by filling in the 'missing'  variable   (V) domain of pT alpha with a V domain from TCR alpha.    Moreover, the proportion of pre-TCR complexes in which the TCR   beta  subunits are accessible to anti-TCR beta antibody   varies with the  cellular context, suggesting that TCR beta   accessibility is controlled  by a trans-acting factor. The   way in which this factor might control TCR  beta   accessibility as well as the physiologic relevance of TCR   beta  masking for pre-TCR function are discussed.

      Address (URL): http://www.ncbi.nlm.nih.gov/pubmed/11058578