Db. Arnold et N. Heintz, A CALCIUM RESPONSIVE ELEMENT THAT REGULATES EXPRESSION OF 2 CALCIUM-BINDING PROTEINS IN PURKINJE-CELLS, Proceedings of the National Academy of Sciences of the United Statesof America, 94(16), 1997, pp. 8842-8847
Calbindin D28 encodes a calcium binding protein that is expressed in t
he cerebellum exclusively in Purkinje cells. We have used biolistic tr
ansfection of organotypic slices of P12 cerebellum to identify a 40-bp
element from the calbindin promoter that is necessary and sufficient
for Purkinje fell specific expression in this transient ipl situ assay
, This element (PCE1) is also present in the calmodulin TI promoter, w
hich regulates expression of a second Purkinje cell Ca2+ binding prote
in, Expression of high levels of exogenous calbindin or calretinin dec
reased transcription mediated by PCE1 in Purkinje cells 2.5- to 3-fold
, whereas the presence of 1 mu M ionomycin in the extracellular medium
increased expression, These results demonstrate that PCE1 is a compon
ent of a cell-specific and Ca2+-sensitive transcriptional regulatory m
echanism that may play a key role in setting the Ca2+ buffering capaci
ty of Purkinje cells.