Purification, characterization, and cloning of a heme-binding protein (23 kDa) in rat liver cytosol

Abstract

A heme-binding protein (designated HBP23) has been purified from rat liver cytosol using heme-affinity chromatography and either reverse-phase high-performance liquid chromatography or sequential ion-exchange chromatography. The protein (23 kDa) binds heme with an affinity (Kd = 55 nM) higher than that of the abundant cytosolic heme-binding proteins, heme-binding protein (HBP)/liver fatty acid-binding protein (L-FABP) and the glutathione S-transferases (GSTs) (Kd = 100-200 nM). HBP23 is present in the cytosol of liver, kidney, spleen, small intestine, and heart, with the liver showing the highest content. A cDNA coding the 23-kDa protein was cloned using reverse transcription polymerase chain reaction with degenerative oligonucleotides derived from partial amino acid sequences. The cloned cDNA encoded 199 amino acids, and its amino acid sequence showed no homology to HBP/L-FABP, GSTs, or any other heme-binding proteins or hemeproteins. Homology search showed that HBP23 is highly homologous to mouse macrophage 23-kDa stress protein, which is inducible by oxidant stress in peritoneal macrophages [Ishii, T., Yamada, M., Sato, H., Matsue, M., Taketani, S., Nakayama, K., Sugita, Y., and Bannai, S. (1993) J. Biol. Chem. 268, 18633-18636]. Thioredoxin peroxidase as well as HBP23 and the mouse macrophage 23-kDa stress protein are members of the peroxiredoxin family, a recently recognized class of antioxidant proteins [Chae, H. Z., Chung, S. J., & Rhee, S. G. (1994) J. Biol. Chem. 269, 27670-27678]. An increase in HBP23 mRNA was observed in Hepa 1-6 cells after treatment with heme and cadmium and during liver regeneration after partial hepatectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of radioprotective peroxiredoxin‐I by ionizing irradiation

“…The same report also documented that overexpression of Prx-II protected cells from gamma irradiation. Cytoprotection by Prx-II in response to numerous stimuli has been well documented by others (Iwahara et al, 1995;Netto et al, 1996;Berggren et al, 2001) and by us . In contrast to the results of Park et al, our results showed that Prx-I, instead of Prx-II, expression was induced by ionizing radiation in human HT29 and rat C6 glioma cells.…”

“…Structure details of several Prx family members have been worked out through X-ray crystallography (Choi et al, 1998;Hirotsu et al, 1999;Schroder et al, 2000). The fact that amino acid sequences and antioxidative functions of Prxs are highly conserved through evolution signifies the importance of these enzymes in cell survival (Shau and Kim, 1994;Iwahara et al, 1995;Prospaeri et al, 1998). Park et al recently showed that levels of human Prx-II were associated with resistance of cells to radiation therapy and that Prx-II antisense served as a radiosensitizer (Park et al, 2000).…”

Oxidative and nitrosative stress induces peroxiredoxins in pancreatic beta cells

“…Peroxiredoxins are in different subcellular compartments. While Prx III is localized to mitochondria [12,22,54,55], Prx I and Prx II are found in the cytoplasm [15,23,32,43]. Furthermore Prx I is thought to be translocated into the nucleus by association with other proteins such as tyrosine kinase c-Abl, though given its small size it could enter passively [34].…”

“…This is reflected by the numerous synonyms used. Thus Prx I is further known as MSP23 (mouse macrophage stress protein M r 23 K) [30], OSF3 (mouse osteoblast specific factor 3) [31], HBP23 (heme-binding protein M r 23 K) [32], PAG (proliferation-associated gene) [10] and NKEF-A (human natural killer cell-enhancing factor-A) [33]. Prx I is a physiological inhibitor of cAbl kinase activity [34].…”

Heme: a versatile signaling molecule controlling the activities of diverse regulators ranging from transcription factors to MAP kinases

“…Interestingly, a 23 kDa heme-binding protein, termed HBP23, is shown to be expressed in the cytosol of the liver, kidney, spleen, small intestine and heart cells [148,149]. Another 21 kDa heme-binding protein, termed p22 HBP, is shown to be induced by heme in mouse erythroleukemia cells [148,150]. These proteins may play important roles in heme metabolism in diverse cells.…”