Phosphatidylinositol 4,5-bisphosphate (PIP2), which comprises only about 1% of the phospholipids in the cytoplasmic leaflet of the plasma membrane, is the source of three second messengers, activates many ion channels and enzymes, is involved in both endocytosis and exocytosis, anchors proteins to the membrane through several structured domains and has other roles. How can a single lipid in a fluid bilayer regulate so many distinct physiological processes? Spatial organization might be the key to this. Recent studies suggest that membrane proteins concentrate PIP2 and, in response to local increases in intracellular calcium concentration, release it to interact with other biologically important molecules.
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http://dx.doi.org/10.1038/nature04398 | DOI Listing |
Cell Mol Neurobiol
January 2025
Laboratory of Neurobiology, Centro de Investigaciones Medico Sanitarias (CIMES), University of Malaga, Calle Marqués de Beccaria, 3, Campus Teatinos s/n, 29010, Malaga, Spain.
Tetrameric AMPA-type ionotropic glutamate receptors are primary transducers of fast excitatory synaptic transmission in the central nervous system, and their properties and abundance at the synaptic surface are crucial determinants of synaptic efficacy in neuronal communication across the brain. The induction of long-term potentiation (LTP) leads to the insertion of GluA1-containing AMPA receptors at the synaptic surface, whereas during long-term depression (LTD), these receptors are internalized into the cytoplasm of the spine. Disruptions in the trafficking of AMPA receptors to and from the synaptic surface attenuate both forms of synaptic plasticity.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Modelling of Cognitive Processes, Berlin Institute of Technology, Berlin 10587, Germany.
Neuronal processing of external sensory input is shaped by internally generated top-down information. In the neocortex, top-down projections primarily target layer 1, which contains NDNF (neuron-derived neurotrophic factor)-expressing interneurons and the dendrites of pyramidal cells. Here, we investigate the hypothesis that NDNF interneurons shape cortical computations in an unconventional, layer-specific way, by exerting presynaptic inhibition on synapses in layer 1 while leaving synapses in deeper layers unaffected.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Biological Sciences, College of Natural Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Bacterial cell wall assembly and remodeling require activities of peptidoglycan (PG) hydrolases as well as PG synthases. In particular, the activity of DD-endopeptidases, which cleave the 4-3 peptide crosslinks in PG, is essential for PG expansion in gram-negative bacteria. Maintaining optimal levels of DD-endopeptidases is critical for expanding PG without compromising its integrity.
View Article and Find Full Text PDFAnal Chem
January 2025
Department of Thoracic Surgery, The Second Hospital of Jilin University, Changchun, Jilin 130041, P. R. China.
Neuropilin 1 (NRP1) is upregulated in various types of malignant tumors, especially non-small-cell lung cancer (NSCLC). However, the precise mechanisms for membrane localization and regulation are not fully understood. Observations from super-resolution microscopy have revealed that NRP1 tends to form nanoscale clusters on the cell membrane, with these clusters varying significantly in size and density across different regions.
View Article and Find Full Text PDFBlood
January 2025
KULeuven, Leuven, Belgium.
Thrombomodulin (TM) expressed on endothelial cells regulates coagulation. Specific nonsense variants in the TM gene, THBD, result in high soluble TM levels causing rare bleeding disorder. In contrast, though THBD variants have been associated with venous thromboembolism, this association remains controversial.
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