Figure 8.

LRPPRC and SLIRP are interdependent and show reduced stability in the absence of mitochondrial mRNA. (A and B) Western blot analyses of SLIRP and LRPPRC in patients with reduced endogenous levels of LRPPRC (A) and human 143B rho⁰ cells (whole cells or mitochondrial fractions as indicated; B) show coordinate decreases in the levels of SLIRP and LRPPRC. Antibodies against the 70-kDa subunit of complex II and against porin were used as loading controls. The lanes labeled COX patients represent patients with uncharacterized COX deficiencies. (C) Coimmunoprecipitation of LRPPRC and SLIRP from mitochondrial extracts of rho⁰ cells. Mitochondria from human rho⁰ cells were extracted and used for IP reactions with the anti-SLIRP antibody as described in Figure 7B. The individual fractions identified at the top of the gel were analyzed by immunoblotting with the anti-LRPPRC and anti-SLIRP antibodies.