» Articles » PMID: 36115019

Characterisation of a Common Hotspot Variant in Acute Intermittent Porphyria Sheds Light on the Mechanism of Hydroxymethylbilane Synthase Function

Overview
Journal FEBS Open Bio
Specialty Biology
Date 2022 Sep 17
PMID 36115019
Authors
Affiliations
Soon will be listed here.
Abstract

Hydroxymethylbilane synthase (HMBS) is the third enzyme involved in haem biosynthesis, in which it catalyses the formation of tetrapyrrole 1-hydroxymethylbilane (HMB). In this process, HMBS binds four consecutive substrate molecules, creating the enzyme-intermediate complexes ES, ES , ES and ES . Pathogenic variants in the HMBS gene are associated with the dominantly inherited disorder acute intermittent porphyria. In this study, we have characterised the p.R26H variant to shed light on the role of Arg26 in the elongation mechanism of HMBS and to provide insights into its effect on the enzyme. With selected biophysical methods, we have been able to show that p.R26H forms a single enzyme-intermediate complex in the ES -state. We were also able to demonstrate that the p.R26H variant results in an inactive enzyme, which is unable to produce the HMB product.

Citing Articles

A case report of acute intermittent porphyria presenting with reversible cerebral vasoconstriction syndrome.

Rao W, Li L, Wu L, Chai W, Li J Medicine (Baltimore). 2025; 104(8):e41526.

PMID: 39993084 PMC: 11856978. DOI: 10.1097/MD.0000000000041526.


Systematically testing human HMBS missense variants to reveal mechanism and pathogenic variation.

van Loggerenberg W, Sowlati-Hashjin S, Weile J, Hamilton R, Chawla A, Sheykhkarimli D Am J Hum Genet. 2023; 110(10):1769-1786.

PMID: 37729906 PMC: 10577081. DOI: 10.1016/j.ajhg.2023.08.012.


Systematically testing human HMBS missense variants to reveal mechanism and pathogenic variation.

van Loggerenberg W, Sowlati-Hashjin S, Weile J, Hamilton R, Chawla A, Gebbia M bioRxiv. 2023; .

PMID: 36798224 PMC: 9934555. DOI: 10.1101/2023.02.06.527353.

References
1.
Poli A, Schmitt C, Moulouel B, Mirmiran A, Talbi N, Riviere S . Givosiran in acute intermittent porphyria: A personalized medicine approach. Mol Genet Metab. 2022; 135(3):206-214. DOI: 10.1016/j.ymgme.2022.01.002. View

2.
Gill R, Kolstoe S, Mohammed F, Al D-Bass A, Mosely J, Sarwar M . Structure of human porphobilinogen deaminase at 2.8 A: the molecular basis of acute intermittent porphyria. Biochem J. 2009; 420(1):17-25. DOI: 10.1042/BJ20082077. View

3.
Bustad H, Kallio J, Laitaoja M, Toska K, Kursula I, Martinez A . Characterization of porphobilinogen deaminase mutants reveals that arginine-173 is crucial for polypyrrole elongation mechanism. iScience. 2021; 24(3):102152. PMC: 7907807. DOI: 10.1016/j.isci.2021.102152. View

4.
Whatley S, Woolf J, Elder G . Comparison of complementary and genomic DNA sequencing for the detection of mutations in the HMBS gene in British patients with acute intermittent porphyria: identification of 25 novel mutations. Hum Genet. 1999; 104(6):505-10. DOI: 10.1007/s004390050995. View

5.
Phillips J . Heme biosynthesis and the porphyrias. Mol Genet Metab. 2019; 128(3):164-177. PMC: 7252266. DOI: 10.1016/j.ymgme.2019.04.008. View