Abstracts » Zoology and wildlife conservation

Changing partners

Article Abstract:

It has been possible to describe the structure of the complex of syntaxin 1a with neuronal Sec1 (nSec1). nSec1 is bound to syntaxin 1a, with syntaxin's H3 helix distorted. It is possible that syntaxin 1a has been shifted into an intermediate conformation, somewhere between closed and open. However, if nSec1 does activate syntaxin 1a, then other components must also be required, as nSec1 alone binds tightly to syntaxin and prevents SNARE-complex assembly. The researchers therefore suggest that SNARE-complex assembly is prompted by other factors, which bind to nSec1. Subsequently, nSec1 changes conformation and releases syntaxin in an open conformation.

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Ca2+-dependent and -independent activities of neural and non-neural synaptotagmins

Article Abstract:

Similar clathrin-AP2 binding properties and particular Ca2+ -dependent interactions with phospholipids and syntaxins are shown by various synaptotagmins (Syts). Interactions of the Syts with neural and non-neural syntaxins depict exocytosis but Syts binding to AP2 indicates endocytosis. The binding character of Syts IV, VI and VIII is Ca2+ -independent. At low concentration of Ca2+, Syts III and VII bind to phopholipids and syntaxins. The Syts I, II and V bind phospholipids at low Ca2+ concentrations and bind syntaxins at high Ca2+ concentrations.

Phospholipids, Exocytosis

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A fusion of new ideas

Article Abstract:

Scientists believe that transport vesicles use v-SNARE-configured proteins from donor organelle membranes to bind with complimentary t-SNARE-configured proteins on the target membrane. The SNARE hypothesis is described in detail. However, recent genetics research shows that an N-ethylmaleimide-sensitive factor (NSF) is also involved in the process before membrane fusion occurs. Further research is required to establish NSF's exact role in the physiological process.

Analysis, Cell research, Cytological research, Genetic research

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