caa a22 4500 475774213 CHVBK 20180406123626.0 cr unu---uuuuu 170329e20000901xx s 000 0 eng 10.1007/s004180000191 doi (NATIONALLICENCE)springer-10.1007/s004180000191 Localization of P32 protein (gC1q-R) in mitochondria and at specific extramitochondrial locations in normal tissues [Elektronische Daten] [Bohdan J. Soltys, Dongchon Kang, Radhey S. Gupta] Abstract.: P32 protein, also known as the gC1q receptor for complement component C1q, is a binding protein for nuclear pre-mRNA splicing factor SF2/ASF and numerous other nuclear and cell surface proteins, yet is targeted to the mitochondrial matrix compartment where these proteins are not present. In the present study, we use immunogold electron microscopy to evaluate the subcellular distribution of P32 protein (gC1q-R) in cultured cell lines and in rat tissues embedded in the acrylic resin LR Gold. Immunogold labeling of Raji lymphoma, CHO, human fibroblasts, HeLa and B-SC-1 cells shows reactivity primarily within mitochondria. Highly specific labeling of mitochondria is also obtained in rat tissues, including adrenal gland, cerebellum, cerebral cortex, heart, kidney, liver, pituitary, pancreas, skeletal muscle, spleen, testes and thyroid. However, strong P32 (gC1q-R) reactivity is also present in (i) zymogen granules, condensing vacuoles, endoplasmic reticulum, and on the cell surface of pancreatic acinar cells, (ii) on the cell surface of microvascular endothelial cells in pancreas and kidney, (iii) on the cell surface and in nuclei of splenic lymphocytes, and (iv) in the acrosome of developing spermatids in testes. Western immunoblots show that the polyclonal antibody to P32 (gC1q-R) used in this study reacts specifically with a 32-kDa protein in both purified pancreatic zymogen granules and in mitochondria, and no other proteins are reactive. These results provide evidence that P32 (gC1q-R) is a mitochondrial protein that also localizes outside mitochondria in certain cells and tissues under normal physiological conditions. Springer-Verlag, 2000 P32 protein Mitochondria Extramitochondrial locations gClq receptor nationallicence Soltys Bohdan J. Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada L8N 3Z5 aut Kang Dongchon Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Faculty of Medicine, Fukuoka 812-82, Japan aut Gupta Radhey S. Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada L8N 3Z5 aut https://doi.org/10.1007/s004180000191 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s004180000191 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Soltys Bohdan J. Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada L8N 3Z5 aut NATIONALLICENCE 700 1- Kang Dongchon Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Faculty of Medicine, Fukuoka 812-82, Japan aut NATIONALLICENCE 700 1- Gupta Radhey S. Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada L8N 3Z5 aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer