Disease relevance of Snapap

• In E. coli MPT83 was expressed as a 23kDa antigen whereas in the rapid growing mycobacterium Mycobacterium smegmatis the protein was expressed as a 25kDa protein indicating post-translational modification of the protein by M. smegmatis [1].

High impact information on Snapap

• Snapin was enriched in neurons and exclusively located on synaptic vesicle membranes [2].
• Snapin: a SNARE-associated protein implicated in synaptic transmission [2].
• In adrenal chromaffin cells, overexpression of the Snapin S50D mutant leads to an increase in the number of release-competent vesicles [3].
• Phosphorylation of Snapin by PKA modulates its interaction with the SNARE complex [3].
• Our results indicate that Snapin may be a PKA target for modulating transmitter release through the cAMP-dependent signal-transduction pathway [3].

Biological context of Snapap

• Thus, our biochemical and electrophysiological studies using snapin knock-out mice demonstrate that Snapin plays a critical role in modulating neurosecretion by stabilizing the release-ready vesicles [4].
• Consequently, the absence of Snapin in embryonic chromaffin cells leads to a significant reduction of calcium-dependent exocytosis resulting from a decreased number of vesicles in releasable pools [4].
• Collectrin bound to SNARE complexes by interacting with snapin, a SNAP-25 binding protein, and facilitated SNARE complex formation [5].

Anatomical context of Snapap

• Furthermore, Snapin is relatively enriched in the purified large dense-core vesicles of chromaffin cells and associated with synaptotagmin-1 [4].
• Moreover, association of Snapin with the plasma membrane was detected in cells overexpressing a Snapin-green fluorescent protein fusion protein [6].
• Subcellular localization experiments revealed that Snapin is a soluble protein that exists in both cytosolic and peripheral membrane-bound pools in adipocytes [6].
• The function of dysbindin-1 in presynaptic, postsynaptic and microtubule locations may all be related to known functions of snapin [7].
• Tissue fractionation of whole mouse brains and human hippocampal formations revealed that both dysbindin-1 and snapin are concentrated in tissue enriched in synaptic vesicle membranes and less commonly in postsynaptic densities [7].

Other interactions of Snapap

• We found that the association of synaptotagmin-1 with SNAP-25 in brain homogenates of snapin mutant mice is impaired [4].
• Interaction between Snapin and G-CSF receptor [8].
• Exo70 competes with SNAP23 for Snapin binding, suggesting that Snapin does not provide a direct link between the exocyst and the SNARE complex but, rather, mediates cross-talk between the two complexes by sequential interactions [9].

Analytical, diagnostic and therapeutic context of Snapap

• Here, the interaction of GCSF-R and Snapin was found by yeast two-hybrid experiment, and the interaction of the two proteins was further confirmed by GST pull-down experiment, mammalian two-hybrid experiment and co-immunoprecipitation study [8].

References