Publications by authors named "Miram Meziane"
Diffusion barriers imposed by tissue topology shape Hedgehog morphogen gradients.
Proc Natl Acad Sci U S A
September 2024
Animals use a small number of morphogens to pattern tissues, but it is unclear how evolution modulates morphogen signaling range to match tissues of varying sizes. Here, we used single-molecule imaging in reconstituted morphogen gradients and in tissue explants to determine that Hedgehog diffused extracellularly as a monomer, and rapidly transitioned between membrane-confined and -unconfined states. Unexpectedly, the vertebrate-specific protein SCUBE1 expanded Hedgehog gradients by accelerating the transition rates between states without affecting the relative abundance of molecules in each state.
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- Animals rely on a few morphogens to shape their tissues, but the mechanism of how evolution adjusts the signaling range of these morphogens for different tissue sizes remains unclear.
- Researchers used advanced imaging techniques to study the Hedgehog morphogen, discovering it moves between different states in a way affected by a protein called SCUBE1, which helps to expand its signaling range without increasing the amount present.
- They proposed a new model that explains how cell gaps act as barriers to morphogen diffusion, suggesting that SCUBE1 aids in overcoming these barriers, leading to a deeper understanding of how morphogen gradients are formed and regulated in different tissues and species.
Spindle positioning must be tightly regulated to ensure asymmetric cell divisions are successful. In budding yeast, spindle positioning is mediated by the asymmetric localization of microtubule + end tracking protein Kar9. Kar9 asymmetry is believed to be essential for spindle alignment.
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