A structure of human Scap bound to Insig-2 suggests how their interaction is regulated by sterols

The sterol regulatory element–binding protein (SREBP) pathway controls cellular homeostasis of sterols. The key players in this pathway, Scap and Insig-1 and -2, are membrane-embedded sterol sensors. The 25-hydroxycholesterol (25HC)–dependent association of Scap and Insig acts as the master switch for the SREBP pathway. Here, we present cryo–electron...

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Sky-high to the sea floor

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Science's new frontier

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A heavy black hole in an x-ray binary

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News at a glance

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Cygnus X-1 contains a 21-solar mass black hole--Implications for massive star winds

The evolution of massive stars is influenced by the mass lost to stellar winds over their lifetimes. These winds limit the masses of the stellar remnants (such as black holes) that the stars ultimately produce. We used radio astrometry to refine the distance to the black hole x-ray binary Cygnus X-1, which we found to be kiloparsecs. When combined...

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WHO's treatment megatrial is at a standstill

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Forming the early heart

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Data in paper about Swedish schoolchildren come under fire

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First in place may not be the winner

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