Mso1 is a probable component of the secretory vesicle docking complex. It interacts with Sec1, which is a Sm-like protein involved in docking and fusion of exocytic vesicles []. The Sec1 binding domain has been identified in the N-terminal region of Mso1 []. This entry represents the N-terminal region (including the Sec1 binding domain) of Mso1.
Sec1-like molecules have been implicated in a variety of eukaryotic vesicle transport processes including neurotransmitter release by exocytosis [].They regulate vesicle transport by binding to a t-SNARE from the syntaxin family. This process is thought to prevent SNARE complex formation, a protein complex required for membrane fusion. Whereas Sec1 molecules are essential for neurotransmitter release and other secretory events, their interaction with syntaxin molecules seems to represent a negative regulatory step in secretion [].
Members of the Sec1 family include Sec1, Sly1, Slp1/Vps33, Vps45/Stt10 (yeast), Unc-18 (nematode), Munc-18b/muSec1, Munc-18c (mouse), Rop (Drosophila), Munc-18/n-Sec1/rbSec1A and rbSec1B (rat) [].Sec1-like molecules have been implicated in a variety of eukaryotic vesicle transport processes including neurotransmitter release by exocytosis [].They regulate vesicle transport by binding to a t-SNARE from the syntaxin family. This process is thought to prevent SNARE complex formation, a protein complex required for membrane fusion. Whereas Sec1 molecules are essential for neurotransmitter release and other secretory events, their interaction with syntaxin molecules seems to represent a negative regulatory step in secretion []. The nSec1 polypeptide chain can be divided into three domains. The first domain, consists of a five-stranded parallel β-sheet flanked by five α-helices. The second domain, like the first one, has an α-β-alpha fold, however the β-sheet of domain 2 features five parallel strands with an additional antiparallel strand on one edge. The third domain is a large insertion between the third and fourth parallel strands of domain 2, and can be subdivided in two [].This superfamily represents the N-terminal region of domain 3 (called domain 3a) found in Sec1 and related proteins.
Members of the Sec1 family include Sec1, Sly1, Slp1/Vps33, Vps45/Stt10 (yeast), Unc-18 (nematode), Munc-18b/muSec1, Munc-18c (mouse), Rop (Drosophila), Munc-18/n-Sec1/rbSec1A and rbSec1B (rat) [].Sec1-like molecules have been implicated in a variety of eukaryotic vesicle transport processes including neurotransmitter release by exocytosis [].They regulate vesicle transport by binding to a t-SNARE from the syntaxin family. This process is thought to prevent SNARE complex formation, a protein complex required for membrane fusion. Whereas Sec1 molecules are essential for neurotransmitter release and other secretory events, their interaction with syntaxin molecules seems to represent a negative regulatory step in secretion []. The nSec1 polypeptide chain can be divided into three domains. The first domain, consists of a five-stranded parallel β-sheet flanked by five α-helices. The second domain, like the first one, has an α-β-alpha fold, however the β-sheet of domain 2 features five parallel strands with an additional antiparallel strand on one edge. The third domain is a large insertion between the third and fourth parallel strands of domain 2, and can be subdivided in two [].This superfamily represents the domain 1 of Sec1 and related proteins.
Sec1-like molecules have been implicated in a variety of eukaryotic vesicle transport processes including neurotransmitter release by exocytosis [].They regulate vesicle transport by binding to a t-SNARE from the syntaxin family. This process is thought to prevent SNARE complex formation, a protein complex required for membrane fusion. Whereas Sec1 molecules are essential for neurotransmitter release and other secretory events, their interaction with syntaxin molecules seems to represent a negative regulatory step in secretion []. The nSec1 polypeptide chain can be divided into three domains. The first domain, consists of a five-stranded parallel β-sheet flanked by five α-helices. The second domain, like the first one, has an α-β-alpha fold, however the β-sheet of domain 2 features five parallel strands with an additional antiparallel strand on one edge. The third domain is a large insertion between the third and fourth parallel strands of domain 2, and can be subdivided in two [].This entry represents domain 2 from the Sec1 family which includes Sec1, Sly1, Slp1/Vps33, yeast Vps45/Stt10, Unc-18 from nematodes, Munc-18b/muSec1, Munc-18c from mouse, Rop from Drosophila, Munc-18/n-Sec1/rbSec1A and rbSec1B from rat [, , , ].
Sec1-like molecules have been implicated in a variety of eukaryotic vesicle transport processes including neurotransmitter release by exocytosis [].They regulate vesicle transport by binding to a t-SNARE from the syntaxin family. This process is thought to prevent SNARE complex formation, a protein complex required for membrane fusion. Whereas Sec1 molecules are essential for neurotransmitter release and other secretory events, their interaction with syntaxin molecules seems to represent a negative regulatory step in secretion []. Mutations in vacuolar protein sorting-associated protein 33B (VPS33B) account for most cases of arthrogryposis, renal dysfunction and cholestasis syndrome (ARC) []. It is proposed that the VPS33 may play a role in vesicle-mediated protein trafficking to lysosomal compartments and in membrane docking/fusion reactions of late endosomes/lysosomes [].
Members of the Sec1 family include Sec1, Sly1, Slp1/Vps33, Vps45/Stt10 (yeast), Unc-18 (nematode), Munc-18b/muSec1, Munc-18c (mouse), Rop (Drosophila), Munc-18/n-Sec1/rbSec1A and rbSec1B (rat) [].The nSec1 polypeptide chain can be divided into three domains. The first domain, consists of a five-stranded parallel β-sheet flanked by five α-helices. The second domain, like the first one, has an α-β-alpha fold, however the β-sheet of domain 2 features five parallel strands with an additional antiparallel strand on one edge. The third domain is a large insertion between the third and fourth parallel strands of domain 2, and can be subdivided in two [].Vacuolar protein sorting-associated protein 33 (Vps33) is essential for vacuolar biogenesis, maturation and function. It is involved in the sorting of vacuolar proteins from the Golgi apparatus and their targeting to the vacuole []. In worm, fly, zebrafish and mammals two homologues of yeast Vps33p have been detected (termed VPS33A and VPS33B in humans). These homologues may reflect the evolution of organelle/tissue-specific functions in multicellular organisms. It is thought that VPS33B may be required for transport to conventional lysosomes, while VPS33A is mainly involved in biogenesis of melanosomes and related lysosomal compartments [, ].This superfamily entry represents the C-terminal region of domain 3 (called domain 3b) found in VPS33.
