This highly authoritative volume highlights the remarkable superfamily of molecular motors called myosins, which are involved in such diverse cellular functions as muscle contraction, intracellular transport, cell migration and cell division. In a timely compilation of chapters written by leading research groups that have made key discoveries in the field, the current understanding of the molecular mechanisms and biological functions of these intriguing proteins is explored.

Myosins are a diverse superfamily of molecular motor proteins, which share the ability to reversibly bind actin and hydrolyse MgATP. They are capable of either translocating actin filaments or translocating vesicles or other cargo on fixed actin filaments. There are currently 15 distinct classes in the myosins superfamily, based on sequence homology. Myosin II and myosin I proteins are familiar and well studied; while Classes III-XV are less well characterized. All myosins examined to date are multimeric and appear to possess at least three functional domains, a head, neck, and tail. Myosins (second edition) explores the structure and functional properties of myosins, their regulation, and mutational analysis. It has been thoroughly updated since the first edition was published in 1995 including sections on the three additional classes defined by new sequences, information provided by the crystal structure of seven new Dicytostelium motor domains, and data from new techniques such as molecular imaging and tagging proteins with GFP 20. The three human diseases that are now known to be linked to mutations in different myosin heavy or light chains are also covered, including more than 50 mutations associated with hyperotrophic cardiomyopathy.

Myosins, actin-dependent molecular motors, are best known for their involvement in muscle contraction. However, besides classical (conventional) myosins, there is a vast number of other myosin motors that structurally and functionally do not resemble muscle myosins and therefore are termed as unconventional myosins. Since discovery in 1973 of the first unconventional myosin, myosin I, in Acanthamoeba castellanii by Thomas D. Pollard and Edward D. Korn, it has been shown that unconventional myosins form a large family, members of which are involved in a plethora of cellular functions, including those associated with intracellular trafficking and cell migration. However, despite the intensive research still many questions persist about their specific role(s) in these processes.

Karp continues to help biologists make important connections between key concepts and experimentation. The sixth edition explores core concepts in considerable depth and presents experimental detail when it helps to explain and reinforce the concepts. The majority of discussions have been modified to reflect the latest changes in the field. The book also builds on its strong illustration program by opening each chapter with “VIP” art that serves as a visual summary for the chapter. Over 60 new micrographs and computer-derived images have been added to enhance the material. Biologists benefit from these changes as they build their skills in making the connection.

This highly authoritative volume highlights the remarkable superfamily of molecular motors called myosins, which are involved in such diverse cellular functions as muscle contraction, intracellular transport, cell migration and cell division. In a timely compilation of chapters written by leading research groups that have made key discoveries in the field, the current understanding of the molecular mechanisms and biological functions of these intriguing proteins is explored.

"CELLS, the most cutting-edge textbook in the field, is the ideal resource for advanced undergraduate and graduate students entering the world of cell biology, and is a useful tool for scientists who wish to learn more about topics outside their field. This important new text provides full coverage of the structure, organization, growth, regulation, movements, and interaction of cells, with an emphasis on eukaryotic cells. Where they are known, the molecular bases for human diseases are discussed in each chapter.Under the direction of Dr. Benjamin Lewin and three expert lead editors, each chapter was prepared by top scientists who specialize in the subject area. All chapters were carefully edited to maintain consistent use of terminology and to achieve a homogeneous level of detail and rigor."--Publisher's website.