the recognition that the endoplasmic reticulum ( er ) , rather than the mitochondria , is the main organelle regulating the cytoplasmic ca2+ concentration in non-muscle cells supports the notion that an alternative physiological role of mitochondrial ca transport is the modulation of ca-sensitive mitochondrial enzymes through small ( micromolar ) fluctuations in the concentration of mitochondrial matrix ca2+ .
C0007634
the
C0010834
cytoplasmic