caa a22 4500 397520433 CHVBK 20180308164631.0 cr unu---uuuuu 161202e199510 xx s 000 0 eng 10.1093/jxb/46.10.1603 doi (NATIONALLICENCE)oxford-10.1093/jxb/46.10.1603 Purification, sequencing and functions of calreticulin from maize [Elektronische Daten] [R.M. Napier, S. Trueman, J. Henderson, J.M. Boyce, C. Hawes, M.D. Fricker, M.A. Venis] The most abundant proteins in the lumen of the endoplasmic reticulum (ER) are thought to be molecular chaperones, some of which might also be involved in calcium storage and release. We have purified calreticulin from maize by ion exchange and reverse-phase chromatography. Identity with plant and animal calreticulins was confirmed by N-terminal amino acid sequencing and it was shown to bind calcium with a calcium overlay technique. An antiserum raised to the purified protein was used to screen an expression library and the full coding sequence for maize calreticulin was determined from the clones selected. The sequence shows 96% identity to barley calreticulin and 55% identity to animal calreticulins. The three major functional regions are conserved, as are targeting and retention features. When visualized by indirect immunofluorescence microscopy, calreticulin was found to be confined to the ER and nuclear envelope of maize root cells. It was distributed throughout the ER compartment and we found no evidence of calreticulin- enriched areas of ER, such as might be associated with specialized calcium storage domains. Increasing or decreasing extracellular calcium did not induce measurable changes in calreticulin levels. In addition, maize calreticulin, as well as other recognized chaperones, was shown to bind to denatured protein and could be eluted specifically by nucleoside trisphosphates. © Oxford University Press Research Papers nationallicence Endoplasmic reticulum nationallicence calcium-binding protein nationallicence immunofluorescence nationallicence targeting nationallicence Zea mays L nationallicence Napier R.M. Horticulture Research International Wellesbourne, Warwick CV35 9EF, UK aut Trueman S. Horticulture Research International Wellesbourne, Warwick CV35 9EF, UK aut Henderson J. Department of Biological and Molecular Sciences, Oxford Brookes University Oxford 0X3 OBP, UK aut Boyce J.M. Department of Plant Sciences, South Parks Road, Oxford University Oxford 0X1 3RB, UK aut Hawes C. Department of Biological and Molecular Sciences, Oxford Brookes University Oxford 0X3 OBP, UK aut Fricker M.D. Department of Plant Sciences, South Parks Road, Oxford University Oxford 0X1 3RB, UK aut Venis M.A. Horticulture Research International Wellesbourne, Warwick CV35 9EF, UK aut Journal of Experimental Botany Oxford University Press 46/10(1995-10), 1603-1613 0022-0957 46:10<1603 1995 46 exbotj https://doi.org/10.1093/jxb/46.10.1603 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.10.1603 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Napier R.M. Horticulture Research International Wellesbourne, Warwick CV35 9EF, UK aut NATIONALLICENCE 700 1- Trueman S. Horticulture Research International Wellesbourne, Warwick CV35 9EF, UK aut NATIONALLICENCE 700 1- Henderson J. Department of Biological and Molecular Sciences, Oxford Brookes University Oxford 0X3 OBP, UK aut NATIONALLICENCE 700 1- Boyce J.M. Department of Plant Sciences, South Parks Road, Oxford University Oxford 0X1 3RB, UK aut NATIONALLICENCE 700 1- Hawes C. Department of Biological and Molecular Sciences, Oxford Brookes University Oxford 0X3 OBP, UK aut NATIONALLICENCE 700 1- Fricker M.D. Department of Plant Sciences, South Parks Road, Oxford University Oxford 0X1 3RB, UK aut NATIONALLICENCE 700 1- Venis M.A. Horticulture Research International Wellesbourne, Warwick CV35 9EF, UK aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/10(1995-10), 1603-1613 0022-0957 46:10<1603 1995 46 exbotj Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford