ALTERATIONS IN CD45 GLYCOSYLATION PATTERN ACCOMPANYING DIFFERENT CELL-PROLIFERATION STATES

CD45 is a leukocyte-specific transmembrane glycoprotein whose intracel lular domain exhibits protein tyrosine phosphatase activity and plays a critical role in signal transduction. CD45 derived from stationary l ymphocytes migrated faster in SDS-PAGE than that derived from exponent ially growing cells. A change in N-linked saccharide structure other t han the neuraminidase-sensitive terminal sialic acid portion was found to be responsible for the molecular size change in CD45. The differen tial glycosylation appeared to occur during late-stage posttranslation al processing of CD45. We speculate that the N-glycosylation differenc e affects the interaction between CD45 and other factors involved in s ignal transduction leading to modulation of leukocyte proliferation. ( C) 1994 Academic Press, Inc.