Characterization of monoclonal antibodies against the T-cell protein tyrosine phosphatase and functional analyses of its promoter

The T cell protein tyrosine phosphatase (TC PTP) has been identified in mice (MPTP or TC PTP), humans (TC PTPa, TC PTPb) and rats (PTPS2, PTPS4). TC PTP has been shown to play an essential role in immune function and its mRNA displays cell cycle dependent expression. In order to describe a panel of five monoclonal antibodies specific to mouse TC PTP, antibody binding properties of mouse, human, rat and monkey TC PTP are characterized using western blotting, immunoprecipitation and immunofluorescence. Furthermore, In order to better understand the upstream elements controlling the expression of the TC PTP gene, approximately 4kb of the murine TC PTP promoter is isolated and characterized. DNA sequencing, primer extension analysis and S1 nuclease mapping are performed and functional promoter activity is determined. In conclusion, although initiator driven transcription allows for ubiquitous expression of TC PTP, general transcription motifs present within the promoter are described that may mediate specific modulations of the TC PTP gene