Hypoxia Associated Proteolytic Processing of OS-9 by the Metalloproteinase Meprin β

Figure 5

Immunoblots for OS-9 and meprin B in MDCK cells exposed to CoCl₂. (a) OS-9 in different cell protein fractions. Protein lysates from MDCK cells were fractionated into a nuclear- and cytosolic-enriched fractions and Western blot analysis used to evaluate the levels of OS-9 in the two fractions. OS-9 was predominantly present in the nuclear-enriched fraction, and the levels decreased following exposure to CoCl₂. (b) Meprin B in meprin β transfected and mock transfected control MDCK cells. The Lipofectamine method coupled with hygromycin supplemented media was used to generate MDCK cells stably transfected with meprin β cDNA. Western blot analysis showed meprin B expression only in the MDCK cells transfected with meprin β cDNA and not the mock transfected control cells. CoCl₂ exposure did not alter meprin B protein expression.

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