PROTEIN-TYROSINE PHOSPHATASES IN T-CELL DEVELOPMENT, APOPTOSIS AND SIGNALING

The study of phosphatases was viewed as a rather esoteric subject for immunologists until eight years ago, when the discovery that CD45 is a protein tyrosine phosphatase (PTPase) began to make the topic respect able. Now, as reviewed by Julie Frearson and Denis Alexander, PTPases are increasingly being shown to play key roles in the molecular physio logy of haematopoietic cells and some have been shown to regulate crit ical events in T-cell development and signalling.