CHARACTERIZATION OF THE CIS-ACTING ELEMENTS OF THE MOUSE MYELIN P2 PROMOTER

Myelin P2 is a basic protein of an apparent molecular weight of 14,800 . Expression Of P2 has been found largely in the cytosol of Schwann ce lls in the peripheral nervous system. Although the function of P2 is u nknown, its striking homology to a family of fatty acid binding protei ns has led to the idea that P2 may function as a fatty acid transport molecule. To investigate the DNA elements that control the expression of P2, sequences 5' to the coding region were cloned upstream of the c at reporter gene. A series of 3' and 5' promoter mutants was construct ed and their activity determined following transfection into secondary Schwann cells and the MT4H1 Schwann cell line. Using this strategy, w e have identified a 217 bp silencer region and a 142 bp positive regul atory region. In addition, we have localized the 5' flanking sequences in the promoter that are responsive to cAMP induction and to the tran scription factor CCAAT/enhancer binding protein (C/EBP). (C) 1993 Wile y-Liss, Inc.