Deficiency in COG5 causes a moderate form of congenital disorders of glycosylation

Paesold-Burda, Patricie; Maag, Charlotte; Troxler, Heinz; Foulquier, François; Kleinert, P.; Schnabel, Siegrun; Baumgartner, Matthias R.; Hennet, Thierry

doi:10.1093/hmg/ddp389

Cited by 99 publications

(89 citation statements)

References 32 publications

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“…Mutations in the genes encoding human COG1, COG4-COG8 have been associated with congenital disorders of glycosylation (CDG) (Foulquier et al, 2006;Foulquier et al, 2007;Kranz et al, 2007;Lübbehusen et al, 2010;Ng et al, 2007;Paesold-Burda et al, 2009;Reynders et al, 2009;Spaapen et al, 2005;Steet and Kornfeld, 2006;Wu et al, 2004) suggesting a role for COG in the retention and/or retrieval of Golgi glycosylation enzymes. Indeed, loss of COG subunits impaired the localisation and the stability of Golgi resident proteins, which are known to recycle within the Golgi stacks (Oka et al, 2004;Zolov and Lupashin, 2005).…”

Section: Discussionmentioning

confidence: 99%

“…In yeast, subunits of Lobe A are essential components of the complex (VanRheenen et al, 1998;Whyte and Munro, 2001;Wuestehube et al, 1996), whereas Lobe B subunits are not substantially required for cell growth or internal membrane organisation (Ram et al, 2002;Whyte and Munro, 2001). Mutations in the genes encoding human COG1, COG4-COG8 have been associated with congenital disorders of glycosylation (CDG) (Foulquier et al, 2006Foulquier et al, 2007Kranz et al, 2007;Lübbehusen et al, 2010;Ng et al, 2007;Paesold-Burda et al, 2009;Reynders et al, 2009;Spaapen et al, 2005;Steet and Kornfeld, 2006;Wu et al, 2004) indicating a role for COG in the transport and/or stability of Golgi glycosylation enzymes. Indeed studies in both yeast and mammalian cells have suggested that COG complex might function as a vesicle-tethering factor in intra-Golgi retrograde COPI transport (Ungar et al, 2002), thus regulating the distribution and the stability of Golgi resident proteins (Oka et al, 2004;Shestakova et al, 2006;Suvorova et al, 2001;Suvorova et al, 2002;Walter et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

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Mutations inCog7affect Golgi structure, meiotic cytokinesis and sperm development duringDrosophilaspermatogenesis

Belloni

Sechi

Riparbelli

et al. 2012

Journal of Cell Science

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SummaryThe conserved oligomeric Golgi (COG) complex plays essential roles in Golgi function, vesicle trafficking and glycosylation. Deletions in the human COG7 gene are associated with a rare multisystemic congenital disorder of glycosylation that causes mortality within the first year of life. In this paper, we characterise the Drosophila orthologue of COG7 (Cog7). Loss-of-function Cog7 mutants are viable but male sterile. The Cog7 gene product is enriched in the Golgi stacks and in Golgi-derived structures throughout spermatogenesis. Mutations in the Cog7 gene disrupt Golgi architecture and reduce the number of Golgi stacks in primary spermatocytes. During spermiogenesis, loss of the Cog7 protein impairs the assembly of the Golgi-derived acroblast in spermatids and affects axoneme architecture. Similar to the Cog5 homologue, four way stop (Fws), Cog7 enables furrow ingression during cytokinesis. We show that the recruitment of the small GTPase Rab11 and the phosphatidylinositol transfer protein Giotto (Gio) to the cleavage site requires a functioning wild-type Cog7 gene. In addition, Gio coimmunoprecipitates with Cog7 and with Rab11 in the testes. Our results altogether implicate Cog7 as an upstream component in a gio-Rab11 pathway controlling membrane addition during cytokinesis.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mutations inCog7affect Golgi structure, meiotic cytokinesis and sperm development duringDrosophilaspermatogenesis

Belloni

Sechi

Riparbelli

et al. 2012

Journal of Cell Science

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“…Recently, COG5 mutations were reported in several CDG patients (24,25,39); substantial clinical overlap between COG5-CDG and COG7-CDG was noted (25). Most of the known COG5-CDG patients carry homozygous nonsense or exon skipping mutations (25,39).…”

Section: Significancementioning

confidence: 99%

“…Most of the known COG5-CDG patients carry homozygous nonsense or exon skipping mutations (25,39). Potentially more informative, from a COG structural standpoint, is a patient with relatively mild symptoms and different mutations in her maternal and paternal copies of the COG5 gene (24,25).…”

Section: Significancementioning

confidence: 99%

Cog5–Cog7 crystal structure reveals interactions essential for the function of a multisubunit tethering complex

Pokrovskaya

Climer

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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The conserved oligomeric Golgi (COG) complex is required, along with SNARE and Sec1/Munc18 (SM) proteins, for vesicle docking and fusion at the Golgi. COG, like other multisubunit tethering complexes (MTCs), is thought to function as a scaffold and/or chaperone to direct the assembly of productive SNARE complexes at the sites of membrane fusion. Reflecting this essential role, mutations in the COG complex can cause congenital disorders of glycosylation. A deeper understanding of COG function and dysfunction will likely depend on elucidating its molecular structure. Despite some progress toward this goal, including EM studies of COG lobe A (subunits 1-4) and higher-resolution structures of portions of Cog2 and Cog4, the structures of COG's eight subunits and the principles governing their assembly are mostly unknown. Here, we report the crystal structure of a complex between two lobe B subunits, Cog5 and Cog7. The structure reveals that Cog5 is a member of the complexes associated with tethering containing helical rods (CATCHR) fold family, with homology to subunits of other MTCs including the Dsl1, exocyst, and Golgi-associated retrograde protein (GARP) complexes. The Cog5-Cog7 interaction is analyzed in relation to the Dsl1 complex, the only other CATCHR-family MTC for which subunit interactions have been characterized in detail. Biochemical and functional studies validate the physiological relevance of the observed Cog5-Cog7 interface, indicate that it is conserved from yeast to humans, and demonstrate that its disruption in human cells causes defects in trafficking and glycosylation.I n eukaryotes, the transport of proteins and lipids among intracellular compartments is mediated by vesicular and tubular carriers under the direction of an elaborate protein machinery (1). Among the most complex and least well-characterized components of this machinery are the multisubunit tethering complexes (MTCs) (2). MTCs are thought to mediate the initial attachment (or tethering) between a trafficking vesicle and its target membrane through a constellation of interactions (3, 4). These may include binding of the MTC to activated Rab GTPases, coiled-coil proteins such as Golgins, vesicle coat proteins, SNAREs, Sec1/ Munc18 (SM) proteins, and/or membrane lipids. Elucidating the 3D structures of MTCs represents an important step toward a better understanding of their molecular functions.Four of the known MTCs-termed complexes associated with tethering containing helical rods (CATCHR) or quatrefoil complexes (2, 5)-contain subunits whose shared 3D structure implies a single evolutionary progenitor (6-16). These CATCHR-family MTCs include the Dsl1, Golgi-associated retrograde protein (GARP), exocyst, and conserved oligomeric Golgi (COG) complexes, and they contain three, four, eight, and eight subunits, respectively. Although X-ray or NMR structures have been reported for 14 of these 23 subunits, only one of the structures contains the full-length polypeptide (14). Perhaps more critically, only two subunit interactions-both wit...

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“…The identification of milder cases of COG6 and COG7 deficiency harboring different mutations [56,57] however shows that the severity of the disease does not simply relate to the subunit affected but rather to the capability of forming a fully functional COG complex. Besides the severe diseases observed for COG6 and COG7 defects, moderate clinical manifestations have been associated with mutations in COG1 [58,59], COG2 [60], COG4 [61,62], and COG5 [63][64][65].…”

Section: Localization Of Glycosyltransferasesmentioning

confidence: 99%

Congenital disorders of glycosylation: a concise chart of glycocalyx dysfunction

Hennet

Cabalzar

2015

Trends in Biochemical Sciences

109

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Glycosylation is a ubiquitous modification of lipids and proteins. Despite the essential contribution of glycoconjugates to the viability of all living organisms, diseases of glycosylation in humans have only been identified over the past few decades. The recent development of next-generation DNA sequencing techniques has accelerated the pace of discovery of novel glycosylation defects. The description of multiple mutations across glycosylation pathways not only revealed tremendous diversity in functional impairments, but also pointed to phenotypic similarities, emphasizing the interconnected flow of substrates underlying glycan assembly. The current list of 100 known glycosylation disorders provides an overview of the significance of glycosylation in human development and physiology. Congenital disorders of glycosylation -a consice chart of glycocalyx dysfunctionThierry Hennet, Jürg Cabalzar Institute of Physiology, University of Zurich, CH-8057 Zurich, Switzerland AbstractGlycosylation is a ubiquitous modification of lipids and proteins. Despite the essential contribution of glycoconjugates to the viability of all living organisms, diseases of glycosylation in humans have only been identified over the past few decades. The recent development of next-generation DNA sequencing techniques has accelerated the pace of discovery of novel glycosylation defects. The description of multiple mutations across glycosylation pathways has revealed a tremendous diversity of functional impairments bus also pointed to phenotypic similarities emphasizing the interconnected flow of substrates underlying glycan assembly. The current list of 100 known glycosylation disorders provides an overview on the significance of glycosylation in human development and physiology. Highlights Congenital disorders underline the role of glycosylation in human development.  Next-gen sequencing techniques expanded the discovery of glycosylation gene defects.  The clinical variability of glycosylation disorders implies they are underdiagnosed. Glycosylation disordersGlycosylation is by far the most complex form of protein [1,2] and lipid modification [3,4] in all domains of life. The tremendous diversity of glycoconjugate structures resulting from intricate biosynthetic pathways is a major factor hampering the assignment of functions to glycans chains. Much has been learnt from the study of disrupted glycosylation genes in model organisms, thereby establishing numerous essential contributions of glycans in regulating cell and organ functions [5]. The study of human diseases of glycosylation brings additional insights by providing a more differentiated view on glycan functions. Indeed, most human mutations are hypomorphic, thus causing partial loss of glycosylation reactions that lead to variable clinical manifestations.Diseases of glycosylation are also referred to as congenital disorders of glycosylation (CDG). Given the heterogeneity of glycans, the clinical scope of CDG is considerable, ranging from nearly normal phenotypes to sever...

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Deficiency in COG5 causes a moderate form of congenital disorders of glycosylation

Cited by 99 publications

References 32 publications

Mutations inCog7affect Golgi structure, meiotic cytokinesis and sperm development duringDrosophilaspermatogenesis

Mutations inCog7affect Golgi structure, meiotic cytokinesis and sperm development duringDrosophilaspermatogenesis

Cog5–Cog7 crystal structure reveals interactions essential for the function of a multisubunit tethering complex

Congenital disorders of glycosylation: a concise chart of glycocalyx dysfunction

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