Subunit composition, protein interactions, and structures of the mammalian brain sec6/8 complex and septin filaments

• Published in: Neuron (Cambridge, Mass.) Vol. 20; no. 6; pp. 1111 - 1122
• Main Authors: Hsu, S C, Hazuka, C D, Roth, R, Foletti, D L, Heuser, J, Scheller, R H
• Format: Journal Article
• Language: English
• Published: United States 01.06.1998
• Subjects: Amino Acid Sequence; Animals; Antibodies; Brain Chemistry - physiology; Carrier Proteins - analysis; Carrier Proteins - metabolism; Carrier Proteins - ultrastructure; Cell Cycle Proteins - analysis; Cell Cycle Proteins - immunology; Cells, Cultured; Cytoskeletal Proteins; Freeze Etching; GTP Phosphohydrolases; Hippocampus - cytology; Mice; Mice, Inbred BALB C; Microfilament Proteins - analysis; Microfilament Proteins - metabolism; Microfilament Proteins - ultrastructure; Molecular Sequence Data; Rabbits; Rats; Schizosaccharomyces pombe Proteins; sec protein; Septins; Spleen - cytology; Synaptic Vesicles - chemistry; Synaptic Vesicles - metabolism; Synaptic Vesicles - ultrastructure; Transcription Factors; Vesicular Transport Proteins
• DOI: 10.1016/s0896-6273(00)80493-6
• ISSN: 0896-6273

Both the sec6/8 complex and septin filaments have been implicated in directing vesicles and proteins to sites of active membrane addition in yeast. The rat brain sec6/8 complex coimmunoprecipitates with a filament composed of four mammalian septins, suggesting an interaction between these complexes. One of the septins, CDC10, displays broad subcellular and tissue distributions and is found in postmitotic neurons as well as dividing cells. Electron microscopic studies showed that the purified rat brain septins form filaments of 8.25 nm in diameter; the lengths of the filaments are multiples of 25 nm. Glutaraldehyde-fixed rat brain sec6/8 complex adopts a conformation resembling the letter "T" or "Y". The sec6/8 and septin complexes likely play an important role in trafficking vesicles and organizing proteins at the plasma membrane of neurons.