The XLR gene product defines a novel set of proteins stabilized in the nucleus by zinc ions.
The major product of the XLR (X-chromosomal, lymphocyte-regulated) locus is found to be a 30-kD nuclear protein with a relatively short (t1/2 approximately equal to 2 h) half-life. Together with its stage- and tissue-specific pattern of expression, this suggests a role for this protein in the regulation of differentiation in T and B lymphocytes. Interestingly, the XLR protein almost completely leaches out of the nucleus after lysis of cells in low salt buffer, but is stabilized in that location by metal cations, particularly Zn++. This stabilization is reversible by chelating agents (o-phenanthroline, EDTA) which also release a number of other polypeptides in addition to XLR. These results suggest that XLR represents a novel class of nuclear proteins, and that cations such as zinc may play a role in the localization of these proteins in the nucleus.
Garchon
H J
HJ
Howard Hughes Medical Institute, Stanford University School of Medicine, California 94305.
Davis
M M
MM
D000818:Animals; D001402:B-Lymphocytes / Q000032:analysis; D002460:Cell Line; D002467:Cell Nucleus / Q000032:analysis*; D004492:Edetic Acid / Q000494:pharmacology; D006207:Half-Life; D051379:Mice; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D010618:Phenanthrolines / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology*
D009687:Nuclear Proteins; D010618:Phenanthrolines; D004492:Edetic Acid; D015032:Zinc; C025205:1,10-phenanthroline