This book is divided into four chapters. The first chapter represents a general review of the literature of relevant topics. Chapter two is a manuscript previously published in the American Journal of Physiology, Cell Physiology, reproduced with the kind permission of the American Physiological Society. This chapter describes the association between beta-tubulin and PKC and reports a novel cell structure dependent on this interaction. Chapter three is a manuscript recently submitted to Acta Physiologica. This paper examines PKC 's association with one of its substrates, calponin (CaP), and the impact of changes in CaP expression levels on -actin cytoskeletal structure. Here we show that calponin may have a novel role in contraction, contributing to actin structural stability through cross-linking of actin filaments. Chapter four contains a brief discussion of the results and implications of both manuscripts, as well as recommendations for future research. In addition to a discussion of the factors contributing to the unique smooth muscle (SM) contraction, a review of certain techniques will follow. These methods were pioneered for use in the study of SM within our laboratory.