Analysis of microtubule dynamics using growth curve models

Abstract

Microtubules are part of the structural network within a cell's cytoplasm, providing structural support as well as taking part in many of the cellular processes. A large body of data provide evidence that dynamics of microtubules in a cell is reponsible for the performance of many critical cellular functions such as cell division. In this article, we study the effect of four different isoforms of a protein tau on microtubule dynamics using growth curve models. The results show that a linear growth curve model is sufficient to explain the data. Moreover, we find that a mutated version of a 3-repeat tau protein has a similar effect as a 4-repeat tau protein on microtubule dynamics. The latter findings conform with the biological understanding of the effect of the protein tau on microtubule dynamics.

Keywords:

• growth curves
• microtubule dynamics
• polynomial regression
• splines
• MANOVA
• Wilks’ Lamda

Acknowledgements

The authors would like to thank Professors Stuart Feinstein and Leslie Wilson as well as Dr Janis Bunker of the Department of Molecular Cellular and Developmental Biology, UCSB for helping us with the biological interpretations and for providing the original data sets. They also wish to express thanks to Professor B.S. Manjunath of the Electrical and Computer Engineering department at UCSB for the opportunity to collaborate on this bioinformatics project.

The authors would also like to thank two anonymous referees for their detailed comments which led to several improvements in the presentation.

The work of Jammalamadaka and Siddiqi was supported by National Science Foundation Grant # ITR-0331697.