scholarly journals On a bender—BARs, ESCRTs, COPs, and finally getting your coat

2011 ◽  
Vol 193 (6) ◽  
pp. 963-972 ◽  
Author(s):  
Mark C. Field ◽  
Andrej Sali ◽  
Michael P. Rout
Keyword(s):  
Comparative Genomics ◽  
Protein Complexes ◽  
Eukaryotic Cell ◽  
Intracellular Membrane ◽  
Membrane Systems ◽  
Profound Impact ◽  
Form And Function ◽  
Evolutionary Origins ◽  
And Function ◽  
Internal Architecture

Tremendous variety in form and function is displayed among the intracellular membrane systems of different eukaryotes. Until recently, few clues existed as to how these internal membrane systems had originated and diversified. However, proteomic, structural, and comparative genomics studies together have revealed extensive similarities among many of the protein complexes used in controlling the morphology and trafficking of intracellular membranes. These new insights have had a profound impact on our understanding of the evolutionary origins of the internal architecture of the eukaryotic cell.

scholarly journals Further twists in gastropod shell evolution

2008 ◽  
Vol 4 (2) ◽  
pp. 179-182 ◽  
Author(s):  
Reuben Clements ◽  
Thor-Seng Liew ◽  
Jaap Jan Vermeulen ◽  
Menno Schilthuizen
Keyword(s):  
Evolutionary Biology ◽  
Logarithmic Spiral ◽  
Spiral Growth ◽  
Evolutionary Perspective ◽  
Gastropod Shell ◽  
Form And Function ◽  
Evolutionary Origins ◽  
Taxonomic Groups ◽  
And Function ◽  
Shell Coiling

The manner in which a gastropod shell coils has long intrigued laypersons and scientists alike. In evolutionary biology, gastropod shells are among the best-studied palaeontological and neontological objects. A gastropod shell generally exhibits logarithmic spiral growth, right-handedness and coils tightly around a single axis. Atypical shell-coiling patterns (e.g. sinistroid growth, uncoiled whorls and multiple coiling axes), however, continue to be uncovered in nature. Here, we report another coiling strategy that is not only puzzling from an evolutionary perspective, but also hitherto unknown among shelled gastropods. The terrestrial gastropod Opisthostoma vermiculum sp. nov. generates a shell with: (i) four discernable coiling axes, (ii) body whorls that thrice detach and twice reattach to preceding whorls without any reference support, and (iii) detached whorls that coil around three secondary axes in addition to their primary teleoconch axis. As the coiling strategies of individuals were found to be generally consistent throughout, this species appears to possess an unorthodox but rigorously defined set of developmental instructions. Although the evolutionary origins of O. vermiculum and its shell's functional significance can be elucidated only once fossil intermediates and live individuals are found, its bewildering morphology suggests that we still lack an understanding of relationships between form and function in certain taxonomic groups.

Form and Function of Facial Expressive Origins

2017 ◽  
Author(s):  
Daniel H. Lee ◽  
Adam K. Anderson
Keyword(s):  
Facial Expressions ◽  
Social Communication ◽  
Visual Information ◽  
Mental States ◽  
Form And Function ◽  
Evolutionary Origins ◽  
Functional Perspective ◽  
Sensory Effects ◽  
And Function ◽  
Communicative Role

Facial expressions are an important source of social communication. But we do not know why they appear the way they do and how they arose. Here we discuss evidence supporting Darwin’s theory that our expressions originated for sensory egocentric function for the expresser, which were then co-opted as signals for allocentric social function. We show that facial expressions of fear and disgust have distinct opposing sensory effects that serve each emotion’s theorized function, regulating the intake of nasal and visual information. Then, we show how such egocentrically adaptive expressive forms may have been socially co-opted for allocentric function, transmitting basic gaze signals and complex mental states adaptively congruent for the receiver as the expresser. Together, the evidence connects the appearance of our expressions from their evolutionary origins to their modern-day communicative role, providing a functional perspective for organizing and understanding expression forms.

scholarly journals The evolutionary origins of antagonistic neurotrophin signaling

2017 ◽  
Vol 216 (5) ◽  
pp. 1223-1225 ◽  
Author(s):  
Austin B. Keeler ◽  
Christopher D. Deppmann
Keyword(s):  
Nervous System ◽  
Effector Proteins ◽  
Competitive Balance ◽  
Form And Function ◽  
Evolutionary Origins ◽  
Survival Pathways ◽  
Toll Receptor ◽  
And Function ◽  
Neurotrophin Signaling ◽  
Receptor Family

A competitive balance between constructive and destructive developmental cues governs both the form and function of the vertebrate nervous system. In this issue, Foldi et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201607098) explore the evolutionary origins of these cues and report that in Drosophila melanogaster pro- and mature neurotrophins are capable of inducing death and survival pathways, respectively, by binding Toll receptor family members, which then recruit distinct sets of effector proteins.

scholarly journals Cities of the Future? The Potential Impact of Artificial Intelligence

AI ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 192-197 ◽  
Author(s):  
Eva Kassens-Noor ◽  
Arend Hintze
Keyword(s):  
Artificial Intelligence ◽  
Urban Growth ◽  
Combined Effects ◽  
Profound Impact ◽  
Form And Function ◽  
The Future ◽  
Ghost Towns ◽  
Potential Impact ◽  
The Many ◽  
And Function

Artificial intelligence (AI), like many revolutionary technologies in human history, will have a profound impact on societies. From this viewpoint, we analyze the combined effects of AI to raise important questions about the future form and function of cities. Combining knowledge from computer science, urban planning, and economics while reflecting on academic and business perspectives, we propose that the future of cities is far from being a determined one and cities may evolve into ghost towns if the deployment of AI is not carefully controlled. This viewpoint presents a fundamentally different argument, because it expresses a real concern over the future of cities in contrast to the many publications who exclusively assume city populations will increase predicated on the neoliberal urban growth paradigm that has for centuries attracted humans to cities in search of work.

scholarly journals Biomedical potential of mammalian spectraplakin proteins: Progress and prospect

2019 ◽  
Vol 244 (15) ◽  
pp. 1313-1322 ◽  
Author(s):  
Sarah A King ◽  
Han Liu ◽  
Xiaoyang Wu
Keyword(s):  
Current Knowledge ◽  
Essential Element ◽  
Eukaryotic Cell ◽  
Form And Function ◽  
Cellular Processes ◽  
Biological Phenomena ◽  
Evolutionarily Conserved ◽  
Inflammatory Bowel ◽  
Cytoskeletal Networks ◽  
And Function

The cytoskeleton is an essential element of a eukaryotic cell which informs both form and function and ultimately has physiological consequences for the organism. Equally as important as the major cytoskeletal networks are crosslinkers which coordinate and regulate their activities. One such category of crosslinker is the spectraplakins, a family of giant, evolutionarily conserved crosslinking proteins with the rare ability to interact with each of the three major cytoskeletal networks. In particular, a mammalian spectraplakin isotype called MACF1 (microtubule actin crosslinking factor 1), also known as ACF7 (actin crosslinking factor 7), has been of particular interest in the years since its discovery; MACF1 has come under such scrutiny due to the mounting list of biological phenomena in which it has been implicated. This review is an overview of the current knowledge on the structure and function of the known spectraplakin isotypes with an emphasis on MACF1, recent studies on MACF1, and finally, an analysis of the potential of MACF1 to advance medicine. Impact statement Spectraplakins are a highly conserved group of proteins which have the rare ability to bind to each of the three major cytoskeletal networks. The mammalian spectraplakin MACF1/ACF7 has proven to be instrumental in many cellular processes (e.g. signaling and cell migration) since its identification and, as such, has been the focus of various research studies. This review is a synthesis of scientific reports on the structure, confirmed functions, and implicated roles of MACF1/ACF7 as of 2019. Based on what has been revealed thus far in terms of MACF1/ACF7’s role in complex pathologies such as metastatic cancers and inflammatory bowel disease, it appears that MACF1/ACF7 and the continued study thereof hold great potential to both enhance the design of future therapies for various diseases and vastly expand scientific understanding of organismal physiology as a whole.

The MICOS complex, a structural element of mitochondria with versatile functions

2020 ◽  
Vol 401 (6-7) ◽  
pp. 765-778
Author(s):  
Siavash Khosravi ◽  
Max E. Harner
Keyword(s):  
Mitochondrial Membrane ◽  
Protein Import ◽  
Current Knowledge ◽  
Protein Complexes ◽  
Inner Mitochondrial Membrane ◽  
Structural Element ◽  
Charcot Marie Tooth Disease ◽  
Form And Function ◽  
Steroidogenic Cells ◽  
And Function

AbstractMitochondria perform a plethora of functions in various cells of different tissues. Their architecture differs remarkably, for instance in neurons versus steroidogenic cells. Furthermore, aberrant mitochondrial architecture results in mitochondrial dysfunction. This indicates strongly that mitochondrial architecture and function are intimately linked. Therefore, a deep knowledge about the determinants of mitochondrial architecture and their function on a molecular level is of utmost importance. In the past decades, various proteins and protein complexes essential for formation of mitochondrial architecture have been identified. Here we will review the current knowledge of the MICOS complex, one of the major structural elements of mitochondria. MICOS is a multi-subunit complex present in the inner mitochondrial membrane. Multiple interaction partners in the inner and outer mitochondrial membrane point to participation in a multitude of important processes, such as generation of mitochondrial architecture, lipid metabolism, and protein import into mitochondria. Since the MICOS complex is highly conserved in form and function throughout evolution, we will highlight the importance of MICOS for mammals. We will emphasize in particular the current knowledge of the association of MICOS with severe human diseases, including Charcot–Marie–Tooth disease type 2, Alzheimer's disease, Parkinson's disease, Frontotemporal Dementia and Amyotrophic Lateral Sclerosis.

Structure of contact sites between the outer and inner mitochondrial membranes investigated by HVEM tomography

1996 ◽  
Vol 54 ◽  
pp. 966-967
Author(s):  
C.A. Mannella ◽  
K.F. Buttle ◽  
K.A. O‘Farrell ◽  
A. Leith ◽  
M. Marko
Keyword(s):  
Liver Mitochondrion ◽  
Adenine Nucleotide ◽  
Protein Complexes ◽  
Mitochondrial Membranes ◽  
Electron Microscopic ◽  
Contact Sites ◽  
Transmission Electron ◽  
Precursor Proteins ◽  
Membrane Contacts ◽  
And Function

Early transmission electron microscopy of plastic-embedded, thin-sectioned mitochondria indicated that there are numerous junctions between the outer and inner membranes of this organelle. More recent studies have suggested that the mitochondrial membrane contacts may be the site of protein complexes engaged in specialized functions, e.g., import of mitochondrial precursor proteins, adenine nucleotide channeling, and even intermembrane signalling. It has been suggested that the intermembrane contacts may be sites of membrane fusion involving non-bilayer lipid domains in the two membranes. However, despite growing interest in the nature and function of intramitochondrial contact sites, little is known about their structure.We are using electron microscopic tomography with the Albany HVEM to determine the internal organization of mitochondria. We have reconstructed a 0.6-μm section through an isolated, plasticembedded rat-liver mitochondrion by combining 123 projections collected by tilting (+/- 70°) around two perpendicular tilt axes. The resulting 3-D image has confirmed the basic inner-membrane organization inferred from lower-resolution reconstructions obtained from single-axis tomography.

Scanning tunneling microscopy (STM) of DNA and RNA

1989 ◽  
Vol 47 ◽  
pp. 34-35
Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans
Keyword(s):  
Molecular Structures ◽  
Inorganic Materials ◽  
Resolving Power ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Form And Function ◽  
Dna And Rna ◽  
Calf Thymus ◽  
And Function ◽  
The Relationship

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).

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