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Origin and evolution of Kinesin-like calmodulin-binding protein
Salah E Abdel-Ghany1, Irene S Day, Mark P Simmons
1Department of Biology, Colorado State University, Fort Collins, Colorado 80523, USA.
Plant Physiology
|June 14, 2005
Summary
Kinesin-like calmodulin-binding protein (KCBP) is found in land plants and green algae, possessing unique domains not present in other kinesins. Its evolutionary origin is linked to sea urchin kinesin-C (SpKinC), with domain acquisition or loss explaining their differences.
Area of Science:
- Molecular Biology
- Evolutionary Biology
- Cell Biology
Background:
- Kinesin-like calmodulin-binding protein (KCBP) is a Kinesin-14 family motor protein characterized by unique myosin tail homology region 4 (MyTH4) and talin-like domains, alongside a calmodulin-binding domain (CBD).
- The presence of MyTH4 and talin-like domains is unusual among kinesins, with only sea urchin kinesin-C (SpKinC) previously reported to possess a CBD.
- KCBP orthologs were notably absent in completed genomes of humans, yeast, worms, flies, and red algae, prompting an investigation into its evolutionary origins.
Purpose of the Study:
- To investigate the evolutionary origin and phylogenetic relationships of Kinesin-like calmodulin-binding protein (KCBP).
- To determine the distribution of KCBP and its unique domains across different species.
- To compare KCBP with the sea urchin kinesin-C (SpKinC) to understand their evolutionary connections.
Main Methods:
- Isolation of KCBP from gymnosperm (Picea abies) and green alga (Stichococcus bacillaris).
- Database searches to identify KCBP in other species, including the green alga Chlamydomonas reinhardtii and various flowering plants.
- Gene tree analysis to determine the phylogenetic placement of KCBP motor domains within the Kinesin-14 family.
Main Results:
- KCBP was identified in green algae and land plants, indicating its conservation within these lineages.
- Gene tree analysis confirmed that KCBP motor domains cluster within the Kinesin-14 family.
- Only land plants and green algae possess kinesins with the MyTH4 and talin-like domains characteristic of KCBP; SpKinC lacks these domains but shares a similar motor domain and CBD.
Conclusions:
- KCBP is a highly conserved protein in green algae and land plants, featuring unique domains not found in other known kinesins.
- The evolutionary analysis suggests that KCBP and SpKinC are closely related, with either KCBP acquiring the MyTH4 and talin-like domains or SpKinC losing them during evolution.
- The study elucidates the evolutionary trajectory of KCBP, highlighting its unique adaptations within the plant and algal lineages.