title: Functional organization of hsp70 cluster in camel (Camelus dromedarius) and other mammals.
abstract: Heat shock protein 70 (Hsp70) is a molecular chaperone providing tolerance to heat and other challenges at the cellular and organismal levels. We sequenced a genomic cluster containing three hsp70 family genes linked with major histocompatibility complex (MHC) class III region from an extremely heat tolerant animal, camel (Camelus dromedarius). Two hsp70 family genes comprising the cluster contain heat shock elements (HSEs), while the third gene lacks HSEs and should not be induced by heat shock. Comparison of the camel hsp70 cluster with the corresponding regions from several mammalian species revealed similar organization of genes forming the cluster. Specifically, the two heat inducible hsp70 genes are arranged in tandem, while the third constitutively expressed hsp70 family member is present in inverted orientation. Comparison of regulatory regions of hsp70 genes from camel and other mammals demonstrates that transcription factor matches with highest significance are located in the highly conserved 250-bp upstream region and correspond to HSEs followed by NF-Y and Sp1 binding sites. The high degree of sequence conservation leaves little room for putative camel-specific regulatory elements. Surprisingly, RT-PCR and 5'/3'-RACE analysis demonstrated that all three hsp70 genes are expressed in camel's muscle and blood cells not only after heat shock, but under normal physiological conditions as well, and may account for tolerance of camel cells to extreme environmental conditions. A high degree of evolutionary conservation observed for the hsp70 cluster always linked with MHC locus in mammals suggests an important role of such organization for coordinated functioning of these vital genes.
authors.affiliation: Engelhardt Institute of Molecular Biology, RAS, Moscow, Russia.
authors.forename: David G
authors.initials: DG
authors.lastname: Garbuz
authors.forename: Lubov N
authors.initials: LN
authors.lastname: Astakhova
authors.forename: Olga G
authors.initials: OG
authors.lastname: Zatsepina
authors.forename: Irina R
authors.initials: IR
authors.lastname: Arkhipova
authors.forename: Eugene
authors.initials: E
authors.lastname: Nudler
authors.forename: Michael B
authors.initials: MB
authors.lastname: Evgen'ev
mesh_terms: D000818:Animals; D001773:Blood Cells / Q000378:metabolism; D015139:Blotting, Southern; D002162:Camelus / Q000235:genetics / Q000378:metabolism*; D021901:DNA, Intergenic / Q000235:genetics; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D008322:Mammals / Q000235:genetics / Q000378:metabolism*; D005810:Multigene Family / Q000235:genetics; D009132:Muscles / Q000378:metabolism; D016366:Open Reading Frames / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D021901:DNA, Intergenic; D018840:HSP70 Heat-Shock Proteins
references.citation: Nucleic Acids Res. 1987 Oct 26;15(20):8125-48
references.pmid: 3313277
references.citation: Science. 2002 Mar 8;295(5561):1852-8
references.pmid: 11884745
references.citation: PLoS One. 2010 May 19;5(5):e10720
references.pmid: 20502665
references.citation: J Exp Biol. 2000 Mar;203(Pt 6):1017-25
references.pmid: 10683161
references.citation: J Biosci. 2007 Apr;32(3):489-99
references.pmid: 17536168
references.citation: Immunogenetics. 1994;39(1):1-7
references.pmid: 7901155
references.citation: Nucleic Acids Res. 2006 Jul 1;34(Web Server issue):W369-73
references.pmid: 16845028
references.citation: J Mol Biol. 1974 Apr 15;84(3):389-98
references.pmid: 4219221
references.citation: Mol Ecol. 2008 Nov;17(21):4763-77
references.pmid: 19140990
references.citation: BMC Evol Biol. 2011 Mar 22;11:74
references.pmid: 21426536
references.citation: Annu Rev Physiol. 1999;61:243-82
references.pmid: 10099689
references.citation: Ann N Y Acad Sci. 2008 Sep;1138:376-84
references.pmid: 18837913
references.citation: Methods Mol Biol. 2000;99:393-419
references.pmid: 10909095
references.citation: Immunogenetics. 1994;40(5):325-30
references.pmid: 7927536
references.citation: J Biol Chem. 1990 Jul 25;265(21):12111-4
references.pmid: 2197269
references.citation: Methods Mol Biol. 1999;112:513-30
references.pmid: 10027274
references.citation: Ann N Y Acad Sci. 2010 Jun;1197:94-107
references.pmid: 20536838
references.citation: Genomics. 1993 Apr;16(1):193-8
references.pmid: 8486356
references.citation: Comp Biochem Physiol B. 1993 Dec;106(4):867-72
references.pmid: 8299349
references.citation: Proc Natl Acad Sci U S A. 1994 Dec 20;91(26):12492-5
references.pmid: 7809064
references.citation: Chromosoma. 2004 Nov;113(5):223-32
references.pmid: 15480729
references.citation: J Clin Invest. 1976 Mar;57(3):604-14
references.pmid: 55418
references.citation: Proc Natl Acad Sci U S A. 1992 Mar 1;89(5):1666-70
references.pmid: 1542659
references.citation: Mol Cell. 2010 Oct 22;40(2):253-66
references.pmid: 20965420
references.citation: BMC Evol Biol. 2008 Jan 23;8:19
references.pmid: 18215318
references.citation: Annu Rev Biochem. 1986;55:1151-91
references.pmid: 2427013