Control of Morphogenesis in Caulobacter Crescentus PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Control of Morphogenesis in Caulobacter Crescentus PDF full book. Access full book title Control of Morphogenesis in Caulobacter Crescentus by Arun Venkat Divakaruni. Download full books in PDF and EPUB format.
Author: Arun Venkat Divakaruni
Publisher:
ISBN:
Category :
Languages : en
Pages : 374
Get Book Here
Book Description
Author: Arun Venkat Divakaruni
Publisher:
ISBN:
Category :
Languages : en
Pages : 374
Get Book Here
Book Description
Author: Christos G. Tsokos
Publisher:
ISBN:
Category :
Languages : en
Pages : 127
Get Book Here
Book Description
Cellular asymmetry is critical to the generation of complexity in both metazoans and many microbes. However, several molecular mechanisms responsible for translating asymmetry into differential cell fates remain unknown. Caulobacter crescentus provides an excellent model to study this process because every division is asymmetric. One daughter cell, the stalked cell, is sessile and commits immediately to S phase. The other daughter, the swarmer cell, is motile and locked in G1. Cellular differentiation requires asymmetric distribution or activation of regulatory factors. In Caulobacter, the master cell cycle regulator CtrA is selectively activated in swarmer cells, deactivated in stalked cells, and reactivated in predivisional cells. CtrA controls DNA replication, polar morphogenesis and cell division, and its cell-type and cell cycle-specific regulation is essential to the life cycle of Caulobacter. In swarmer cells, activated CtrA binds to the origin of replication and holds cells in G1. In stalked cells, CtrA deactivation allows for the initiation of DNA replication. Finally, in predivisional cells, CtrA is reactivated and acts as a transcription factor for>100 genes including those involved in polar morphogenesis and cell division. CtrA regulation is determined by the polarly localized histidine kinase CckA, but how CckA is differentially regulated in each cell type and why activity depends on localization are unknown. This thesis demonstrates that the unorthodox kinase DivL promotes CckA activity and that the phosphorylated regulator DivK inhibits CckA by binding to DivL. Differential cellular fates are achieved by regulating the phosphorylation state of DivK. In swarmer cells, DivK is dephosphorylated, thereby activating CckA and arresting the cells in G1. In stalked cells, phosphorylated DivK inactivates CckA, thus allowing for DNA replication initiation. Paradoxically, in predivisional cells, while phosphorylated DivK levels remain high, CckA is reactivated to initiate cellular division and morphogenesis. CckA activation in this cell type relies on polar localization with a DivK phosphatase. Localization thus creates a protected zone for CckA within the cell, without the use of membrane-enclosed compartments. These results reveal the mechanisms by which CckA is regulated in a cell-type-dependent manner. More generally, these findings reveal how cells exploit subcellular localization to orchestrate sophisticated regulation.
Author: Jan Löwe
Publisher: Springer
ISBN: 331953047X
Category : Science
Languages : en
Pages : 457
Get Book Here
Book Description
This book describes the structures and functions of active protein filaments, found in bacteria and archaea, and now known to perform crucial roles in cell division and intra-cellular motility, as well as being essential for controlling cell shape and growth. These roles are possible because the cytoskeletal and cytomotive filaments provide long range order from small subunits. Studies of these filaments are therefore of central importance to understanding prokaryotic cell biology. The wide variation in subunit and polymer structure and its relationship with the range of functions also provide important insights into cell evolution, including the emergence of eukaryotic cells. Individual chapters, written by leading researchers, review the great advances made in the past 20-25 years, and still ongoing, to discover the architectures, dynamics and roles of filaments found in relevant model organisms. Others describe one of the families of dynamic filaments found in many species. The most common types of filament are deeply related to eukaryotic cytoskeletal proteins, notably actin and tubulin that polymerise and depolymerise under the control of nucleotide hydrolysis. Related systems are found to perform a variety of roles, depending on the organisms. Surprisingly, prokaryotes all lack the molecular motors associated with eukaryotic F-actin and microtubules. Archaea, but not bacteria, also have active filaments related to the eukaryotic ESCRT system. Non-dynamic fibres, including intermediate filament-like structures, are known to occur in some bacteria.. Details of known filament structures are discussed and related to what has been established about their molecular mechanisms, including current controversies. The final chapter covers the use of some of these dynamic filaments in Systems Biology research. The level of information in all chapters is suitable both for active researchers and for advanced students in courses involving bacterial or archaeal physiology, molecular microbiology, structural cell biology, molecular motility or evolution. Chapter 3 of this book is open access under a CC BY 4.0 license.
Author: Yiyin Erin Chen
Publisher:
ISBN:
Category :
Languages : en
Pages : 210
Get Book Here
Book Description
Asymmetric cell division allows for better environmental adaptation and organismal complexity. Cells often divide by binary fission to form two identical daughter cells with similar developmental fates. However, a cell can also divide asymmetrically to form two daughter cells with different developmental fates. This process makes possible diverse behaviors such as differing life cycles respondent to environmental stimuli and specialization of cellular functions to generate organ systems. How cells divide asymmetrically and how they enforce the differential fates of daughter cells remain unsolved, fundamental problems in biology. In this work, I use the model organism Caulobacter crescentus to investigate how intracellular asymmetry within the mother cell is translated into the formation of two developmentally distinct daughter cells. Caulobacter is an alpha-proteobacterium that always divides asymmetrically to generate two daughter cells that are morphologically distinct and have different replicative capacities. I show that kinase and phosphatase activities at opposite poles of the cell generate a spatial gradient in the phosphorylation level of an essential cell cycle regulator called CtrA. This spatial gradient of CtrA phosphorylation enforces replicative asymmetry and couples it to the asymmetric morphogenesis of the daughter cells. I then investigate how CtrA's control of replicative asymmetry relates to the control of replication periodicity. I show that the activity of an essential replication initiator DnaA dictates the timing of replication initiation and oscillates independently of CtrA activity. The genetic separability of the spatial and temporal controls of replication in Caulobacter suggests that DnaA comprises an ancient and phylogenetically widespread control module for replication in almost all bacteria while CtrA developed later in c-proteobacteria and was recruited to enforce replicative asymmetry in daughter cells. This work provides a foundation for understanding cellular asymmetry and evolution of the cell cycle in bacteria.
Author: James A. Hoch
Publisher: Amer Society for Microbiology
ISBN: 9781555810894
Category : Medical
Languages : en
Pages : 488
Get Book Here
Book Description
The human enteroviruses, particularly the polio viruses, have had a significant role in the history of medicine and microbiology; and continue to cause clinical problems, as well as provide targets for molecular investigation. This book offers a link between the basic science and clinical medicine.
Author: Gregory R. Bock
Publisher: John Wiley and Sons
ISBN: 9780471496625
Category : Science
Languages : en
Pages : 274
Get Book Here
Book Description
This book brings together scientists working at the interface between the cell cycle, cell growth and development in a variety of model systems and research paradigms. The focus is on understanding how such diverse developmental inputs can modulate cell cycle regulation and, reciprocally, how a common way of regulating cell cycle progression can participate in different developmental strategies.
Author: Masayori Inouye
Publisher: Elsevier
ISBN: 0080534015
Category : Science
Languages : en
Pages : 539
Get Book Here
Book Description
Living cells are constantly sensing environmental changes, and their abilities to sense these changes and adapt to them are essential for their survival. In bacteria, histidine kinases are the major sensors for these environmental stresses, enabling cells to adapt to new growth conditions. Written by leading experts in the field, this book provides an up-to-date and comprehensive review on the structure and function of histidine kinases. It also provides extensive information on the physiological roles of histidine kinases in bacteria and eukaryotes. An an essential reference for cell biologists, microbiologists, molecular biologists, and biochemists interested in signal transduction. Experimental biologists and pharmacologists studying signal transduction systems in living organisms will also find it a valuable research tool. The first comprehensive book on the roles of histidine kinases in cells 23 in-depth chapters written by leading experts in the field Describes the most recent advances in the field of signal transduction
Author: Jean-Pierre Tassan
Publisher: Springer
ISBN: 3319531506
Category : Science
Languages : en
Pages : 421
Get Book Here
Book Description
This book provides readers with an overview of the frequent occurrence of asymmetric cell division. Employing a broad range of examples, it highlights how this mode of cell division constitutes the basis of multicellular organism development and how its misregulation can lead to cancer. To underline such developmental correlations, readers will for example gain insights into stem cell fate and tumor growth. In turn, subsequent chapters include descriptions of asymmetric cell division from unicellular organisms to humans in both physiological and pathological conditions. The book also illustrates the importance of this process for evolution and our need to understand the background mechanisms, offering a valuable guide not only for students in the field of developmental biology but also for experienced researchers from neighboring fields.
Author: J. Reinert
Publisher: Springer Science & Business Media
ISBN: 354037390X
Category : Science
Languages : en
Pages : 336
Get Book Here
Book Description
It is instructive to compare the response of biologists to the two themes that comprise the title of this volume. The concept of the cell cycle-in contra distinction to cell division-is a relatively recent one. Nevertheless biologists of all persuasions appreciate and readily agree on the central problems in this area. Issues ranging from mechanisms that initiate and integrate the synthesis of chro mosomal proteins and DNA during S-phase of mitosis to the manner in which assembly of microtubules and their interactions lead to the segregation of metaphase chromosomes are readily followed by botanists and zoologists, as well as by cell and molecular biologists. These problems are crisp and well-defined. The current state of "cell differentiation" stands in sharp contrast. This, one of the oldest problems in experimental biology, almost defies definition today. The difficulties arise not only from a lack of pertinent information on the regulatory mechanisms, but also from conflicting basic concepts in this field. One of the ways in which this situation might be improved would be to find a broader experimental basis, including a better understanding of the relationship between the cell cycle and cell differentiation.
Author: Walid El-Sharoud
Publisher: Springer Science & Business Media
ISBN: 3540749217
Category : Science
Languages : en
Pages : 377
Get Book Here
Book Description
The application of new molecular methodologies in the study of bacterial behavior and cell architecture has enabled new revolutionary insights and discoveries in these areas. This new text presents recent developments in bacterial physiology that are highly relevant to a wide range of readership including those interested in basic and applied knowledge. Its chapters are written by international scientific authorities at the forefront of the subject. The value of this recent knowledge in bacterial physiology is not only restricted to fundamental biology. It also extends to biotechnology and drug-discovery disciplines.
