Analysis of a naturally occurring mutation in sucrase–isomaltase: glutamine 1098 is not essential for transport to the surface of COS-1 cells

Ouwendijk, Joke; Peters, W.H.M.; Morsche, R.H.M. te; Vorstenbosch, R.A. van de; Ginsel, L.A.; Naim, Hassan Y.; Fransen, J.A.M.

doi:10.1016/s0925-4439(98)00016-7

Cited by 5 publications

(4 citation statements)

References 23 publications

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“…What is the role of the Q 1098 residue in this context? We have previously shown by site-directed mutagenesis of Q 1098 that the intracellular transport of SI to the cell surface is not affected by Q 1098 (Ouwendijk et al, 1998). We corroborated these data by alanine scanning at Q 1098 itself.…”

Section: Resultssupporting

confidence: 79%

“…The deficiency is based on a point mutation in the SI gene that results in a substitution of a glutamine by proline at amino acid residue 1098 of the sucrase subunit (Q1098P) (Moolenaar et al, 1997;Ouwendijk et al, 1996). This mutation is found in a region that has strong homologies with some members of the family of glycosyl hydrolases (Moolenaar et al, 1997;Naim et al, 1991;Ouwendijk et al, 1998) in mammalian cells and also in the yeast Schwanniomyces occidentalis. Strikingly, substitution of the glutamine residue with proline at the corresponding position of human lysosomal α-glucosidase, resulted in its retention in ERGIC and cis-Golgi (Moolenaar et al, 1997) thus generating a similar phenotype to that of SI (denoted throughout SI Q1098P ).…”

Section: Introductionmentioning

confidence: 99%

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A phenylalanine-based folding determinant in intestinal sucrase-isomaltase that functions in the context of a quality control mechanism beyond the endoplasmic reticulum

Pröpsting¹,

Jacob

Naim³

2005

Journal of Cell Science

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Phenotype II of congenital sucrase-isomaltase deficiency in man is characterized by a retention of the brush border protein sucrase-isomaltase (SI) in the ER/cis-Golgi intermediate compartment (ERGIC) and the cis-Golgi. The transport block is due to the substitution of a glutamine by a proline at amino acid residue 1098 that generates a temperature-sensitive mutant enzyme, SIQ1098P, the transport of which is regulated by several cycles of anterograde and retrograde transport between the ER and the cis-Golgi (Propsting, M. J., Jacob, R. and Naim, H. Y. (2003). J. Biol. Chem. 278, 16310-16314). A quality control beyond the ER has been proposed that implicates a retention signal or a folding determinant elicited by the Q1098P mutation. We have used alanine-scanning mutagenesis to screen upstream and downstream regions flanking Q1098 and identified a putative motif, F1093-x-F1095-x-x-x-F1099 that is likely to be implicated in sensing the folding and subsequent trafficking of SI from the ER to the Golgi. The characteristics of this motif are three phenylalanine residues that upon substitution by alanine generate the temperature-sensitive SIQ1098P phenotype. This mutant protein undergoes transport arrest in the ERGIC and cis-Golgi compartments and acquires correct folding and functional activity at reduced temperatures as a consequence of cycles of anterograde and retrograde transport between the ER and cis-Golgi. Other amino acid residues in this motif are not significant in the context of phenotype II. We propose that the phenylalanine cluster is required for shielding a folding determinant in the extracellular domain of SI; substitution of a Q by a P at residue 1098 of sucrase disrupts this determinant and elicits retention of SIQ1098P in ERGIC and cis-Golgi in phenotype II of CSID.

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Section: Resultssupporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

A phenylalanine-based folding determinant in intestinal sucrase-isomaltase that functions in the context of a quality control mechanism beyond the endoplasmic reticulum

Pröpsting¹,

Jacob

Naim³

2005

Journal of Cell Science

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“…Due to the limited amount of the biopsy specimen, we were not able to investigate the biosynthesis and processing of the SI complex in organ culture as has been performed with other cases of CSID (8,22). However, the tissue available was adequate for the isolation of the cDNA encoding the patient's SI by reverse transcriptase-PCR following a similar strategy to that described previously (22,23). The correctness of the cDNA was corroborated by sequencing in both directions 5Ј-3Ј and vice versa (24).…”

Section: Resultsmentioning

confidence: 99%

Molecular Basis of Aberrant Apical Protein Transport in an Intestinal Enzyme Disorder

Spodsberg¹,

Jacob²,

Alfalah³

et al. 2001

Journal of Biological Chemistry

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The impaired sorting profile to the apical membrane of human intestinal sucrase-isomaltase is the underlying cause in the pathogenesis of a novel phenotype of intestinal congenital sucrase-isomaltase deficiency. Molecular characterization of this novel phenotype reveals a point mutation in the coding region of the sucraseisomaltase (SI) gene that results in an amino acid substitution of a glutamine by arginine at residue 117 of the isomaltase subunit. This substitution is located in a domain revealing features of a trefoil motif or a P-domain in immediate vicinity of the heavily O-glycosylated stalk domain. Expression of the mutant SI phenotype in epithelial Madin-Darby canine kidney cells reveals a randomly targeted SI protein to the apical and basolateral membranes confirming an exclusive role of the Q117R mutation in generating this phenotype. Unlike wild type SI, the mutant protein is completely extractable with Triton X-100 despite the presence of O-glycans that serve in the wild type protein as an apical sorting signal and are required for the association of SI with detergent-insoluble lipid microdomains. Obviously the O-glycans are not adequately recognized in the context of the mutant SI, most likely due to altered folding of the Pdomain that ultimately affects the access of the O-glycans to a putative sorting element.The composition and function of the plasma membrane of polarized cells are maintained by a complex intracellular traffic moving cell surface glycoproteins between organelles. This requires the recognition and sorting of different classes of proteins not only during biosynthesis, but also during distributive events to the diverse cellular compartments (1). Oftentimes altered and defective intracellular trafficking of proteins due to single point or deletion mutations in the coding region of the gene result in pathological disorders (2, 3). Investigating the molecular basis of naturally occurring mutant protein phenotypes in diseases constitutes therefore a powerful means to unravel the molecular mechanisms underlying intracellular protein transport and sorting. A small intestinal disorder directly associated with a folding mutant and defective intracellular protein transport is congenital sucrase-isomaltase deficiency (CSID).1 CSID is an autosomal recessive disease that is characterized by an absent sucrase activity within the sucraseisomaltase (SI) enzyme complex, while the isomaltase activity can vary from absent to normal. The disease is clinically manifested as an osmotic-fermentative diarrhea upon ingestion of di-and oligosaccharides (4). Several phenotypes of the disease have been characterized on the basis of cellular mislocalization or aberrant function of the SI mutant protein. SI is a type II membrane-bound glycoprotein of the intestinal brush border comprising two strongly homologous subunits, sucrase and isomaltase (5-8). These two domains originate from a large polypeptide precursor, pro-SI, by tryptic cleavage occurring in the intestinal lumen and ultimately maintain a strong a...

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“…Studies on the sucrase-isomaltase protein in individuals of European extraction suggest that various different mutations cause the deficiency, and so far three exonic mutations have been identified. One results in substitution of proline by a glutamine at amino acid 1098 (Ouwendijk et al 1998) and one causes the protein to be secreted (Jacob et al 2000), and one glutamine by arginine 117 affects apical protein transport (Spodsberg et al 2001). It is not known whether any one mutation occurs at higher frequency.…”

Section: Sucrase-isomaltase Deficiencymentioning

confidence: 99%

Genetic influences on carbohydrate digestion

Swallow¹

2003

NRR

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The diversity of the human genome leads to many functional differences between individuals. The present review focuses on genetic variations, both rare and common, that are of relevance to digestion of the sugars and starches that form a major part of human diets, and considers these in relation to the evolution of our species. For example, intolerances of dietary saccharides are not usually life-threatening because symptoms can be avoided by removal of the offending sugar from the diet, and deficiencies of the relevant enzymes are in some cases found at relatively high frequencies in certain populations. This is of evolutionary interest in relation to changes in the human diet, and the lactase-persistence polymorphism, in particular, provides an interesting model. More of the world's adult population are lactase-deficient than have high lactase. The other deficiencies are however much more rare, but the significance of variant alleles at these loci, and also heterozygosity for deficiency alleles, to human nutrition and health is an area that is relatively unexplored.

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Analysis of a naturally occurring mutation in sucrase–isomaltase: glutamine 1098 is not essential for transport to the surface of COS-1 cells

Cited by 5 publications

References 23 publications

A phenylalanine-based folding determinant in intestinal sucrase-isomaltase that functions in the context of a quality control mechanism beyond the endoplasmic reticulum

A phenylalanine-based folding determinant in intestinal sucrase-isomaltase that functions in the context of a quality control mechanism beyond the endoplasmic reticulum

Molecular Basis of Aberrant Apical Protein Transport in an Intestinal Enzyme Disorder

Genetic influences on carbohydrate digestion

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