Fig. 3.
Subcellular localization and membrane topology of HIMP1. (A) Examination of HIMP1 in αTC1.6 cells, cardiomyocytes, and mature sperm by immunoelectron microscopy. (B) In vitro synthesized [35S]HIMP1-a protein with/without microsomes was subjected to digestion with Tc and separation by SDS/PAGE gel for autoradiography. (C) Immunoprecipitants with anti-HIMP1 serum from aliquots treated with/without Tc of translation products in B were subjected to SDS/PAGE for autoradiography. (D) Membrane topology sketch of HIMP1-a, as determined in the in vitro system. (E) Immunoblot analysis of HIMP1in mitochondrial outer and inner membrane fractions treated with or without Tc. Outer M, outer membrane fraction; mitoplast, inner membrane and matrix. (F) Membrane orientation sketch of HIMP1 determined in mitochondria from αTC1.6 cells. N, N-terminal; C, C-terminal; M, membrane.