Effect of Cysteamine on Mutant ASL Proteins with Cysteine for Arginine Substitutions.

Inauen, Corinne; Rüfenacht, Véronique; Pandey, Amit Vikram; Hu, Liyan; Blom, Henk; Nuoffer, Jean-Marc; Häberle, Johannes (2016). Effect of Cysteamine on Mutant ASL Proteins with Cysteine for Arginine Substitutions. Molecular diagnosis & therapy, 20(2), pp. 125-133. Springer 10.1007/s40291-015-0182-z

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INTRODUCTION

Cysteamine is used to treat cystinosis via the modification of cysteine residues substituting arginine in mutant proteins.

OBJECTIVES

We investigated the effect of cysteamine on mutant argininosuccinate lyase (ASL), the second most common defect in the urea cycle.

METHODS

In an established mammalian expression system, 293T cell lysates were produced after transfection with all known cysteine for arginine mutations in the ASL gene (p.Arg94Cys, p.Arg95Cys, p.Arg168Cys, p.Arg379Cys, and p.Arg385Cys), allowing testing of the effect of cysteamine over 48 h in the culture medium as well as for 1 h immediately prior to the enzyme assay.

RESULTS

Cysteamine at low concentrations showed no effect on 293T cell viability, ASL protein expression, or ASL activity when applied during cell culture. However, incubation of transfected cells with 0.05 mM cysteamine immediately before the enzyme assay resulted in increased ASL activity of p.Arg94Cys, p.Arg379Cys, and p.Arg385Cys by 64, 20, and 197 %, respectively, and this result was significant (p < 0.01). Cell lysates carrying p.Arg385Cys and treated with cysteamine recover enzyme activity that is similar to the untreated designed mutation p.Arg385Lys, providing circumstantial evidence for the assumed cysteamine-induced change of a cysteine to a lysine analogue.

CONCLUSION

Since 12 % of all known genotypes in ASL deficiency are affected by a cysteine for arginine mutation, we conclude that the potential of cysteamine or of related substances as remedy for this disease should be investigated further.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Pre-clinic Human Medicine > BioMedical Research (DBMR) > Unit Childrens Hospital > Forschungsgruppe Endokrinologie / Diabetologie / Metabolik (Pädiatrie)

UniBE Contributor:

Pandey, Amit Vikram

Subjects:

500 Science > 570 Life sciences; biology
600 Technology > 610 Medicine & health

ISSN:

1179-2000

Publisher:

Springer

Language:

English

Submitter:

Amit Vikram Pandey

Date Deposited:

21 Sep 2016 15:30

Last Modified:

04 Jun 2020 13:57

Publisher DOI:

10.1007/s40291-015-0182-z

PubMed ID:

26745957

BORIS DOI:

10.7892/boris.88466

URI:

https://boris.unibe.ch/id/eprint/88466

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