Motor-powered movement along microtubule tracks is important for membrane organization and trafficking. However, the molecular basis for membrane transport is poorly understood, in part because of the difficulty in reconstituting this process from purified components. Using video microscopic observation of organelle transport in vitro as an assay, we have purified two polypeptides (245 and 170 kD) from Dictyostelium extracts that independently reconstitute plus-end-directed membrane movement at in vivo velocities. Both polypeptides were found to be kinesin motors, and the 245-kD protein (DdUnc104) is a close relative of Caenorhabditis elegans Unc104 and mouse KIF1A, neuron-specific motors that deliver synaptic vesicle precursors to nerve terminals. A knockout of the DdUnc104 gene produces a pronounced defect in organelle transport in vivo and in the reconstituted assay. Interestingly, DdUnc104 functions as a dimeric motor, in contrast to other members of this kinesin subfamily, which are monomeric.
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http://dx.doi.org/10.1083/jcb.147.3.493 | DOI Listing |
Protein Sci
February 2025
Cell Physiology and Molecular Biophysics Department, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.
Purifying membrane proteins has been the limiting step for studying their structure and function. The challenges of the process include the low expression levels in heterologous systems and the requirement for their biochemical stabilization in solution. The human voltage-gated proton channel (hH1) is a good example of that: the published protocols to express and purify hH1 produce low protein quantities at high costs, which is an issue for systematically characterizing its structure and function.
View Article and Find Full Text PDFCell Mol Biol Lett
January 2025
University Cote d'Azur, Inserm, C3M, Nice, France.
Vacuolization of hematopoietic precursors cells is a common future of several otherwise non-related clinical settings such as VEXAS, Chediak-Higashi syndrome and Danon disease. Although these disorders have a priori nothing to do with one other from a clinical point of view, all share abnormal vacuolization in different cell types including cells of the erythroid/myeloid lineage that is likely the consequence of moderate to drastic dysfunctions in the ubiquitin proteasome system and/or the endo-lysosomal pathway. Indeed, the genes affected in these three diseases UBA1, LYST or LAMP2 are known to be direct or indirect regulators of lysosome trafficking and function and/or of different modes of autophagy.
View Article and Find Full Text PDFSci Rep
January 2025
School of Agriculture and Food Systems, Davis College of Agriculture and Natural Resources, West Virginia University, Morgantown, WV, USA.
The management of micronutrients, such as boron (B) and zinc (Zn), is critical for plant growth and crop yields. One method of rapid intervention crop management to mitigate nutritional deficiency is the foliar supply of B and Zn. Our study investigates the effect of foliar-supplied B and Zn availability on the global transcriptional modulation in soybean (Glycine max).
View Article and Find Full Text PDFJ Exp Bot
January 2025
National Institute of Science and Technology on Plant Physiology under Stress Conditions, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, Minas Gerais, Brazil.
The transport of metabolites across the inner mitochondrial membrane (IMM) is crucial for maintaining energy balance and efficient distribution of metabolic intermediates between cellular compartments. Under abiotic stress, mitochondrial function becomes particularly critical, activating complex signaling pathways essential for plant stress responses. These pathways modulate stress-responsive gene expression, influencing key physiological processes such as cell respiration and senescence, helping plants adapt to stress.
View Article and Find Full Text PDFBiophys J
January 2025
Theoretical Physics of Living Matter, Institute of Biological Information Processing and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany. Electronic address:
Translocation across barriers and through constrictions is a mechanism that is often used in vivo for transporting material between compartments. A specific example is apicomplexan parasites invading host cells through the tight junction that acts as a pore, and a similar barrier crossing is involved in drug delivery using lipid vesicles penetrating intact skin. Here, we use triangulated membranes and energy minimization to study the translocation of vesicles through pores with fixed radii.
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