Characterization of cyclin-dependent kinases and their expression in developing maize endosperm

Persistent Link:
http://hdl.handle.net/10150/195599
Title:
Characterization of cyclin-dependent kinases and their expression in developing maize endosperm
Author:
Dante, Ricardo Augusto
Issue Date:
2005
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
During maize endosperm development, cells switch from mitotic into endoreduplication cell cycles, concomitant with the differentiation of starchy endosperm cells. The identity and role of cyclins and cyclin-dependent kinases (CDKs) that control these cell cycles are poorly understood. I identified and characterized maize cyclins of the D- (CYCD2;1 and CYCD5;1) and A1-types (CYCA1;3) that are expressed in endosperm. CYCA1;3 RNA decreased sharply as the endosperm transitioned from the mitotic to the endoreduplication stage, whereas CYCD2;1 and CYCD5;1 transcripts declined gradually. Polyclonal antibodies against CYCA1;3, CYCD5;1, and CYCD2;1 and a B-type homologue, CYCB1;3, were used to characterize cyclin protein accumulation, the associated CDK activity, and spatial localization of cyclins in endosperm. Except for CYCA1;3, cyclin protein levels were nearly constant or decreased slightly throughout development. CDK activity associated with CYCA1;3 was most abundant 7 days after pollination (DAP), while that associated with CYCB1;3, CYCD2;1 and CYCD5;1 peaked at 11 DAP. CYCA1;3 appeared to be most abundant in the cytoplasm of non-endoreduplicating cells. CYCB1;3 and CYCD2;1 were found throughout the endosperm, while CYCD5;1 was mostly localized in aleurone and subaleurone cells. Stability assays using in vitro-synthesized cyclins showed that CYCA1;3, CYCB1;3, CYCD2;1 and CYCD5;1 were degraded to a large extent via the proteasome in mitotic but not in endoreduplicating endosperm extracts. The results suggest that cyclin proteolysis may not play a major role in controlling endoreduplication cell cycles in maize endosperm. I identified and characterized maize CDKs of the A- (CDKA;3) and B- (CDKB1;1 and CDKB2;1) types that are expressed in developing endosperm. Their transcripts were more abundant during the mitotic than the endoreduplication stage of development. Polyclonal antibodies that specifically recognized CDKA;3 and CDKA;1, and CDKB1;1, were obtained. A-type CDK protein levels were nearly constant, while those of CDKB1;1 decreased abruptly during endosperm development. CDKB1;1 extracted from 9-DAP endosperm bound p13suc1 in vitro, suggesting that CDKB1;1 contributes to mitotic CDK activity at early stages of endosperm development. In co-expression experiments in Drosophila S2 cells, CDKA;1 and CDKA;1 formed catalytically active complexes with CYCD2;1 and inactive complexes with CYCB1;3 and CYCD5;1.
Type:
text; Electronic Dissertation
Keywords:
Plant Science
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Plant Science; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Larkins, Brian A
Committee Chair:
Larkins, Brian A

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleCharacterization of cyclin-dependent kinases and their expression in developing maize endospermen_US
dc.creatorDante, Ricardo Augustoen_US
dc.contributor.authorDante, Ricardo Augustoen_US
dc.date.issued2005en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractDuring maize endosperm development, cells switch from mitotic into endoreduplication cell cycles, concomitant with the differentiation of starchy endosperm cells. The identity and role of cyclins and cyclin-dependent kinases (CDKs) that control these cell cycles are poorly understood. I identified and characterized maize cyclins of the D- (CYCD2;1 and CYCD5;1) and A1-types (CYCA1;3) that are expressed in endosperm. CYCA1;3 RNA decreased sharply as the endosperm transitioned from the mitotic to the endoreduplication stage, whereas CYCD2;1 and CYCD5;1 transcripts declined gradually. Polyclonal antibodies against CYCA1;3, CYCD5;1, and CYCD2;1 and a B-type homologue, CYCB1;3, were used to characterize cyclin protein accumulation, the associated CDK activity, and spatial localization of cyclins in endosperm. Except for CYCA1;3, cyclin protein levels were nearly constant or decreased slightly throughout development. CDK activity associated with CYCA1;3 was most abundant 7 days after pollination (DAP), while that associated with CYCB1;3, CYCD2;1 and CYCD5;1 peaked at 11 DAP. CYCA1;3 appeared to be most abundant in the cytoplasm of non-endoreduplicating cells. CYCB1;3 and CYCD2;1 were found throughout the endosperm, while CYCD5;1 was mostly localized in aleurone and subaleurone cells. Stability assays using in vitro-synthesized cyclins showed that CYCA1;3, CYCB1;3, CYCD2;1 and CYCD5;1 were degraded to a large extent via the proteasome in mitotic but not in endoreduplicating endosperm extracts. The results suggest that cyclin proteolysis may not play a major role in controlling endoreduplication cell cycles in maize endosperm. I identified and characterized maize CDKs of the A- (CDKA;3) and B- (CDKB1;1 and CDKB2;1) types that are expressed in developing endosperm. Their transcripts were more abundant during the mitotic than the endoreduplication stage of development. Polyclonal antibodies that specifically recognized CDKA;3 and CDKA;1, and CDKB1;1, were obtained. A-type CDK protein levels were nearly constant, while those of CDKB1;1 decreased abruptly during endosperm development. CDKB1;1 extracted from 9-DAP endosperm bound p13suc1 in vitro, suggesting that CDKB1;1 contributes to mitotic CDK activity at early stages of endosperm development. In co-expression experiments in Drosophila S2 cells, CDKA;1 and CDKA;1 formed catalytically active complexes with CYCD2;1 and inactive complexes with CYCB1;3 and CYCD5;1.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectPlant Scienceen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePlant Scienceen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorLarkins, Brian Aen_US
dc.contributor.chairLarkins, Brian Aen_US
dc.contributor.committeememberSchumaker, Karen S.en_US
dc.contributor.committeememberYadegari, Raminen_US
dc.contributor.committeememberJorgensen, Richard A.en_US
dc.contributor.committeememberLeonard, Robert T.en_US
dc.identifier.proquest1040en_US
dc.identifier.oclc137353651en_US
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