Eukaryotic DING proteins are endogenous: an immunohistological study in mouse tissues.
BACKGROUND
DING proteins encompass an intriguing protein family first characterized by their conserved N-terminal sequences. Some of these proteins seem to have key roles in various human diseases, e.g., rheumatoid arthritis, atherosclerosis, HIV suppression. Although this protein family seems to be ubiquitous in eukaryotes, their genes are consistently lacking from genomic databases. Such a lack has considerably hampered functional studies and has fostered therefore the hypothesis that DING proteins isolated from eukaryotes were in fact prokaryotic contaminants.


RESULTS
In the framework of our study, we have performed a comprehensive immunological detection of DING proteins in mice. We demonstrate that DING proteins are present in all tissues tested as isoforms of various molecular weights (MWs). Their intracellular localization is tissue-dependant, being exclusively nuclear in neurons, but cytoplasmic and nuclear in other tissues. We also provide evidence that germ-free mouse plasma contains as much DING protein as wild-type.


CONCLUSIONS
Hence, data herein provide a valuable basis for future investigations aimed at eukaryotic DING proteins, revealing that these proteins seem ubiquitous in mouse tissue. Our results strongly suggest that mouse DING proteins are endogenous. Moreover, the determination in this study of the precise cellular localization of DING proteins constitute a precious evidence to understand their molecular involvements in their related human diseases.
Collombet
Jean-Marc
JM
Département de Toxicologie, Institut de Recherche Biomédicale des Armées, Centre de Recherche du Service de Santé des Armées, La Tronche, France.
Elias
Mikael
M
Gotthard
Guillaume
G
Four
Elise
E
Renault
Frédérique
F
Joffre
Aurélie
A
Baubichon
Dominique
D
Rochu
Daniel
D
Chabrière
Eric
E
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D015153:Blotting, Western; D001923:Brain Chemistry; D002540:Cerebral Cortex / Q000737:chemistry / Q000166:cytology; D005057:Eukaryotic Cells / Q000378:metabolism*; D006624:Hippocampus / Q000737:chemistry / Q000166:cytology; D007150:Immunohistochemistry; D008099:Liver / Q000737:chemistry; D008168:Lung / Q000737:chemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D008970:Molecular Weight; D009474:Neurons / Q000737:chemistry; D063150:Polycomb Repressive Complex 1; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D012097:Repressor Proteins / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D012867:Skin / Q000737:chemistry; D044767:Ubiquitin-Protein Ligases; D016335:Zinc Fingers
D000911:Antibodies, Monoclonal; D020033:Protein Isoforms; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1; C489842:Rnf2 protein, mouse; D044767:Ubiquitin-Protein Ligases