tailieunhanh - Báo cáo khoa học: Gene duplication and separation of functions in aB-crystallin from zebrafish (Danio rerio)

We previously reported that zebrafishaB-crystallin is not constitutively expressed in nervous or muscular tissue and has reduced chaperone-like activity compared with its human ortholog. Here we characterize the tissue expression pattern and chaperone-like activity of a second zebrafish aB-crystallin. | ềFEBS Journal Gene duplication and separation of functions in aB-crystallin from zebrafish Danio rerio Amber A. Smith1 Keith Wyatt2 Jennifer Vacha1 Thomas S. Vihtelic3 J. S. Zigler Jr4 Graeme J. Wistow2 and Mason Posner1 1 Department of Biology Ashland University OH USA 2 Section on Molecular Structure and FunctionalGenomics NationalEye Institute Bethesda MD USA 3 University of Notre Dame Center for Zebrafish Research and Department of BiologicalSciences Notre Dame IN USA 4 Lens and Cataract Biology Section NationalEye Institute Bethesda MD USA Keywords crystallins heat shock proteins lens molecular chaperones zebrafish Correspondence M. Posner Department of Biology Ashland University 401 College Avenue Ashland OH 44805 USA Fax 419 289 5283 Tel 419 289 5691 E-mail mposner@ Website http mposner Note These authors contributed equally to this work. Received 3 September 2005 revised 22 November 2005 accepted 29 November 2005 doi We previously reported that zebrafish aB-crystallin is not constitutively expressed in nervous or muscular tissue and has reduced chaperone-like activity compared with its human ortholog. Here we characterize the tissue expression pattern and chaperone-like activity of a second zebrafish aB-crystallin. Expressed sequence tag analysis of adult zebrafish lens revealed the presence of a novel a-crystallin transcript designated cryab2 and the resulting protein aB2-crystallin. The deduced protein sequence was and identical with human aB-crystallin and zebrafish aB1-crystallin respectively. RT-PCR showed that aB2-crystallin is expressed predominantly in lens but reminiscent of mammalian aB-crystallin also has lower constitutive expression in heart brain skeletal muscle and liver. The chaperone-like activity of purified recombinant aB2 protein was assayed by measuring its ability to prevent the chemically induced aggregation of a-lactalbumin and lysozyme. At 25 C and 30 C zebrafish