Molecular Characterization of a Newly Identified Heme-binding Protein Induced during Differentiation of urine Erythroleukemia Cells

Abstract

A heme-binding protein with a molecular mass of 22 kDa, termed p22 HBP, was purified from mouse liver cytosol, using blue Sepharose CL-6B. We identified a cDNA encoding p22 HBP, and sequence analysis revealed that p22 HBP comprises 190 amino acid residues (M r 21,063) and has no homology to any other known heme-binding protein.

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.…”

Sequence Analysis of LRPPRC and Its SEC1 Domain Interaction Partners Suggests Roles in Cytoskeletal Organization, Vesicular Trafficking, Nucleocytosolic Shuttling, and Chromosome Activity

“…1, 5). A homologue of C6ORF34 (HBP) was first isolated from liver on the basis of its heme-binding property that can be competed by nontetrapyrrole ligands as palmitic acid and all-trans-retinoic acid [37]. These properties suggest a potential link of the LRPPCR-C6ORF34 to heme metabolism, redox status and oxygen sensing that may link to transcription complexes.…”

Involvement of PLAGL2 in activation of iron deficient- and hypoxia-induced gene expression in mouse cell lines

“…Total RNA was isolated from RAW264.7, Balb/c 3T3 and MEL cells (1610 7 ), using the guanidium isothiocyanate method, as described (Taketani et al, 1998). Ten mg of RNA were loaded on a 1% agarose/formaldehyde gel, electrophoresed, transferred onto nylon membrane (Amersham, Hybond N+) for hybridization with the 32 P-labeled fragments of mouse PLAGL2 and ZAC1 cDNAs (Taketani et al, 1998), then the ®lter was hybridized and washed, as described (Taketani et al, 1998).…”

“…Ten mg of RNA were loaded on a 1% agarose/formaldehyde gel, electrophoresed, transferred onto nylon membrane (Amersham, Hybond N+) for hybridization with the 32 P-labeled fragments of mouse PLAGL2 and ZAC1 cDNAs (Taketani et al, 1998), then the ®lter was hybridized and washed, as described (Taketani et al, 1998). Intensity of the bands was quanti®ed using an Advantec DMU-33c densitometer.…”

“…Total RNA was isolated from RAW264.7 cells (2610 7 ) cultured with or without 100 mM desferrioxamine for 16 h, and poly(A) + RNA was enriched using oligo(dT) cellulose, as described previously (Taketani et al, 1998). Reverse transcription was done using 2 mg of mRNA from RAW264.7 cells cultured under the two conditions.…”