Figure 1.

STIM expression in the Xenopus oocyte and its downregulation by as-STIM injection. A) shows the RT-PCR amplification of products that corresponded to the size expected for either stim1 or stim2 in native oocytes (CNT); the corresponding amplicons were absent in oocytes from the same batch that had been injected with either as-STIM1 or as-STIM2 48 h before the assay. The rps2 amplicon indicates the reaction efficiency, and -RT and H₂O lanes correspond to negative controls, either RNA without RT, or to the reaction mix without a cDNA template, respectively. B) STIM1 and STIM2 were identified by Western blot analysis in protein extracts from oocytes (Oo) or mouse brain (MB, positive control) using either NH-STIM1 (left panel) or COOH-STIM2 (right panel) as antibody. C) A similar analysis as in B was made for batches of oocytes injected with H₂O as control (CNT), or with as-STIM1 or as-STIM2 48 h before the protein extraction, in which cases proteins were eliminated. (in all cases 10 oocytes per condition).