Disease relevance of CYB561

• However, in B-cell lymphomas such as Burkitt's and Daudi, the cytochrome b561 expression was completely shut down [1].

High impact information on CYB561

• These include, as Fe(II), facilitating the production of dopamine from phenylalanine by tyrosine hydroxylase, and as heme, assisting the recycling of ascorbate by cytochrome b-561 required for the generation of norepinephrine from dopamine by dopamine beta-hydroxylase [2].
• Dysfunction of cytochrome b-561 or stromal cell-derived receptor 2, therefore, might predispose individuals to abnormal accumulation of Fe(III) and/or generation of cytotoxic free radicals as a consequence of a rapid cycling between Fe(III) and Fe(II) [2].
• Human Erythrocyte Membranes Contain a Cytochrome b561 That May Be Involved in Extracellular Ascorbate Recycling [3].
• Cytochrome b561 is an electron transfer protein unique to neuroendocrine secretory vesicles [1].
• Genomic structure and expression of the human gene encoding cytochrome b561, an integral protein of the chromaffin granule membrane [1].

Biological context of CYB561

• In this report, we describe the cloning and properties of a full-length cDNA encoding human neuroendocrine cytochrome b561 from a human caudate cDNA library and a human peripheral blood genomic library [4].
• One of the most important potential roles of cytochrome b561 is that it can be used as a model protein to investigate long-range biological electron transport [5].
• Most species contain three or four cytochrome b561 paralogous proteins, and the encoding genes usually have four or five exons [6].

Anatomical context of CYB561

• Human cytochrome b561: a revised hypothesis for conformation in membranes which reconciles sequence and functional information [4].
• An ascorbate-reducible cytochrome b561 is localized in macrophage lysosomes [7].
• Purified cytochrome b561 from bovine adrenal medulla chromaffin vesicles has been reconstituted into phosphatidylcholine vesicles by a detergent-dialysis method [8].
• In this study, we characterized wild watermelon cytochrome b561 (cyt b561), which potentially mediates regeneration of apoplastic ascorbate by transferring electrons from cytosolic ascorbate across the plasma membrane [9].
• The presence of cytochrome b561 was studied further by reverse transcriptase-PCR analysis of erythrocyte progenitor cells, reticulocytes [10].

Associations of CYB561 with chemical compounds

• Cytochrome b561, reduced upon flash excitation, is re-oxidized slowly even in the absence of antimycin [11].
• Selective Perturbation of the Intravesicular Heme Center of Cytochrome b561 by Cysteinyl Modification with 4,4'-Dithiodipyridine [12].
• In chromatophores there were no detectable differences between wild type (Wt) and mutant M234EV with respect to cytochrome b-561 reduction following a flash, and no effect of bicarbonate depletion (by incubation with formate) [13].

Other interactions of CYB561

• To validate the microarray results, we confirmed the enhanced expression of a few selected SA genes, i.e., gpr1, apo-D, apo-E, apo-L, mmp-1, mmp-3, cyb561, cyp1b1, and cyp4b1, by reverse transcription-PCR [14].
• Identification of an ascorbate-dependent cytochrome b of the tonoplast membrane sharing biochemical features with members of the cytochrome b561 family [15].
• Spectroscopic analysis of erythrocyte membrane preparations revealed the presence of cytochrome b5 and hemoglobin but also of a cytochrome with properties similar to cytochrome b561, reducible by ascorbate and insensitive to CO [10].
• The membranes of these vesicles contain the typical large dense cored vesicle markers dopamine- -hydroxylase, synaptotagmin, cytochrome b561 and rab 3 [16].

Analytical, diagnostic and therapeutic context of CYB561

• Optical redox titrations of partially purified cytochrome b-561 indicated that it contains two hemes with similar spectral features, but distinct midpoint redox potentials (E(m7)+135 mV and +206 mV, respectively) [17].

References