A Globin in the Nucleus!*

Cytoglobin and neuroglobin are recently discovered members of the globin family. In situ hybridization localized neuroglobin mainly in brain and retina, while cytoglobin was expressed ubiquitously in all analyzed tissues. In the present study, polyclonal antibodies were raised against both proteins and the distribution of them was studied by immunocytochemistry at tissue and subcellular level. Cytoglobin immunoreactivity was uniformly distributed and found in all tissues studied. At the subcellular level, cytoglobin immunoreactivity was exclusively detected in the cell nucleus. In contrast, neuroglobin immunoreactivity was detected in specific brain regions with varying intensities and in the islet of Langerhans in the pancreas. The immunoreactivity was restricted to the cytoplasm of neurons and endocrine beta cells. The nuclear localization of cytoglobin opens new perspectives for possible function(s) of globin-folded proteins as transcriptional regulators.

[1]  U. Flögel,et al.  Myoglobin facilitates oxygen diffusion. , 2001, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[2]  J. Stamler,et al.  Ascaris haemoglobin is a nitric oxide-activated ‘deoxygenase’ , 1999, Nature.

[3]  Alessandra Pesce,et al.  Neuroglobin and cytoglobin , 2002, EMBO reports.

[4]  T. Spiro,et al.  Heme-based sensors: theoretical modeling of heme-ligand-protein interactions. , 2001, Current opinion in chemical biology.

[5]  M. Blaxter,et al.  A Hemoglobin with an Optical Function* , 2000, The Journal of Biological Chemistry.

[6]  Thomas Hankeln,et al.  A vertebrate globin expressed in the brain , 2000, Nature.

[7]  D. Rousseau,et al.  A cooperative oxygen-binding hemoglobin from Mycobacterium tuberculosis. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[8]  Martino Bolognesi,et al.  Truncated Hemoglobins: A New Family of Hemoglobins Widely Distributed in Bacteria, Unicellular Eukaryotes, and Plants* 210 , 2002, The Journal of Biological Chemistry.

[9]  M. Bolognesi,et al.  Nonvertebrate hemoglobins: structural bases for reactivity. , 1997, Progress in biophysics and molecular biology.

[10]  V. Sivozhelezov,et al.  A globin-coupled oxygen sensor from the facultatively alkaliphilic Bacillus halodurans C-125 , 2001, Extremophiles.

[11]  D. B. Kristensen,et al.  Characterization of a Stellate Cell Activation-associated Protein (STAP) with Peroxidase Activity Found in Rat Hepatic Stellate Cells* , 2001, The Journal of Biological Chemistry.

[12]  K. Rodgers.  Heme-based sensors in biological systems. , 1999, Current opinion in chemical biology.

[13]  Marc Schmidt,et al.  How Does the Eye Breathe? , 2003, The Journal of Biological Chemistry.

[14]  T. Townes,et al.  Basic Residues within the Kruppel Zinc Finger DNA Binding Domains Are the Critical Nuclear Localization Determinants of EKLF/KLF-1* , 2002, The Journal of Biological Chemistry.

[15]  R. Kerby,et al.  CooA, a CO-sensing transcription factor from Rhodospirillum rubrum, is a CO-binding heme protein. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[16]  M. Gilles-Gonzalez,et al.  Dos, a heme-binding PAS protein from Escherichia coli, is a direct oxygen sensor. , 2000, Biochemistry.

[17]  M. Gilles-Gonzalez,et al.  Oxygen Signal Transduction , 2001, IUBMB life.

[18]  R. Hill,et al.  Altering hemoglobin levels changes energy status in maize cells under hypoxia. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[19]  M. Hargrove,et al.  A Ubiquitously Expressed Human Hexacoordinate Hemoglobin* , 2002, The Journal of Biological Chemistry.

[20]  L Orci,et al.  Endocrine pancreas: three-dimensional reconstruction shows two types of islets of langerhans. , 1979, Science.

[21]  K. Imai.  Physiology: The haemoglobin enzyme , 1999, Nature.

[22]  T. Burmester,et al.  Cytoglobin: a novel globin type ubiquitously expressed in vertebrate tissues. , 2002, Molecular biology and evolution.

[23]  D. B. Kristensen,et al.  Characterization of human stellate cell activation-associated protein and its expression in human liver. , 2002, Biochimica et biophysica acta.

[24]  S. Reuss,et al.  Expression analysis of neuroglobin mRNA in rodent tissues , 2002, Neuroscience.

[25]  L. Gonyea.  Purification and iodination of antibody for use in an immunoradiometric assay for serum ferritin. , 1977, Clinical chemistry.

[26]  Jean-Pierre Timmermans,et al.  Triple Immunofluorescence Staining with Antibodies Raised in the Same Species to Study the Complex Innervation Pattern of Intrapulmonary Chemoreceptors , 2002, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[27]  J. Richardson,et al.  Neuroglobin, A Novel Member of the Globin Family, Is Expressed in Focal Regions of the Brain , 2002, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[28]  E. Brambilla,et al.  F(ab) secondary antibodies: a general method for double immunolabeling with primary antisera from the same species. Efficiency control by chemiluminescence. , 1994, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[29]  S. McKnight,et al.  NPAS2: An Analog of Clock Operative in the Mammalian Forebrain , 2001, Science.

[30]  Nitric oxide dioxygenase: an enzymic function for flavohemoglobin. , 1998 .

[31]  S N Vinogradov,et al.  Nonvertebrate hemoglobins: functions and molecular adaptations. , 2001, Physiological reviews.

[32]  J. Tata.  [24] Isolation of nuclei from liver and other tissues , 1974 .

[33]  A. Howard,et al.  Vitreoscilla Hemoglobin Binds to Subunit I of Cytochrome bo Ubiquinol Oxidases* , 2002, The Journal of Biological Chemistry.

[34]  M. Costa,et al.  Light and electron microscopic immunocytochemistry of the same nerves from whole mount preparations. , 1985, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[35]  J. Bieker,et al.  Krüppel-like Zinc Fingers Bind to Nuclear Import Proteins and Are Required for Efficient Nuclear Localization of Erythroid Krüppel-like Factor* , 2002, The Journal of Biological Chemistry.

[36]  L. Moens,et al.  Biochemical Characterization and Ligand Binding Properties of Neuroglobin, a Novel Member of the Globin Family* , 2001, The Journal of Biological Chemistry.

[37]  S. McKnight,et al.  NPAS2: A Gas-Responsive Transcription Factor , 2002, Science.

[38]  U. Francke,et al.  Molecular characterization of two mammalian bHLH-PAS domain proteins selectively expressed in the central nervous system. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[39]  R. Watts,et al.  Human Neuroglobin, a Hexacoordinate Hemoglobin That Reversibly Binds Oxygen* , 2001, Journal of Biological Chemistry.

[40]  R. Hardison,et al.  Hemoglobins from bacteria to man: evolution of different patterns of gene expression. , 1998, The Journal of experimental biology.

[41]  D. J. Schuller,et al.  Structure of the CO sensing transcription activator CooA , 2000, Nature Structural Biology.

[42]  M. Bolognesi,et al.  Unusual structure of the oxygen-binding site in the dimeric bacterial hemoglobin from Vitreoscilla sp. , 1997, Structure.

[43]  M. Brunori,et al.  Nitric oxide moves myoglobin centre stage. , 2001, Trends in biochemical sciences.

[44]  Jared Rutter,et al.  Regulation of Clock and NPAS2 DNA Binding by the Redox State of NAD Cofactors , 2001, Science.

[45]  J. Dawson,et al.  Studies of the heme coordination and ligand binding properties of soluble guanylyl cyclase (sGC): characterization of Fe(II)sGC and Fe(II)sGC(CO) by electronic absorption and magnetic circular dichroism spectroscopies and failure of CO to activate the enzyme. , 1995, Biochemistry.

[46]  I. Vass,et al.  Nuclear localization of a hypoxia‐inducible novel non‐symbiotic hemoglobin in cultured alfalfa cells1 , 2000, FEBS letters.