Isolation and characterization of a calmodulin-like domain protein kinase cDNA from the moss Tortula ruralis / by Susan L. McKnight.
| Author/creator | McKnight, Susan L. author. |
| Other author | Putnam-Evans, Cindy, degree supervisor. |
| Other author | East Carolina University. Department of Biology. |
| Format | Theses and dissertations |
| Production | 1998. |
| Description | ix, 80 leaves : illustrations ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | Calmodulin-like Domain Protein Kinases (CDPK) represent a family of widely distributed calcium-regulated enzymes found predominantly in plants and protists. Their structure consists of a variable amino terminal domain of unknown function, a kinase catalytic domain, a highly conserved autoregulatory domain, and a calmodulin-like domain at the carboxy terminus. They are activated upon the direct binding of calcium and require neither calmodulin nor phospholipids for activation. The first plant CDPK was purified and characterized from soybean suspension cultures. Since then, the presence of CDPKs has been demonstrated in many vascular plant species, green algae and protists. The purpose of this research was to isolate and characterize a CDPK from a member of the Bryophyte family of nonvascular plants. A cDNA library constructed from the dehydrated moss Tortula ruralis was screened using an 828 bp probe corresponding to kinase subdomain Vlb through EF-hand III of the full length CDPK, AK1, from Arahidopsis thaliana. Positive clones from quaternary screening were subjected to in vivo excision and restriction digestion. The clone containing the largest insert was subjected to automated DNA sequencing using a battery of primers. Sequence for a 2243 bp full length CDPK clone was obtained which contains the four domain structures typical of CDPKs. Genomic DNA was subjected to Southern hybridization using the full-length moss cDNA as a probe. The presence of single bands in each digest lane suggests that CDPKs in T. ruralis, unlike in higher plants. are products of a single gene. Northern analysis demonstrated that the CDPK mRNA is expressed only in T. ruralis plants which have been subjected to desiccation alone or desiccation plus rehydration. This suggests a possible role for moss CDPKs in the process of desiccation tolerance. |
| General note | Submitted to the faculty of the Department of Biology. |
| General note | Advisor: Cindy Putnam-Evans |
| Dissertation note | M.S. East Carolina University 1998 |
| Bibliography note | Includes bibliographical references (leaves 73-80). |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |