Part:BBa_K2539250

ALDH2*2 Basic Part

This gene codes for the mutant form of human mitochondrial acetaldehyde dehydrogenase, ALDH2*2, which metabolizes acetaldehyde at a slower rate compared to the wild type form, ALDH2*1 (Chen et al., 2014).

ALDH2*2 is common in East Asia, and people carrying this mutant form are considered ALDH2 deficient. ALDH2 deficiency, more commonly known as Alcohol flushing syndrome or Asian glow, interferes with the metabolism of alcohol. ALDH2*2 is slow to convert acetaldehyde, a toxic intermediate, into acetate (Chen et al., 2014). As a result, acetaldehyde accumulates and induces an inflammatory reaction that causes the skin to flush or appear red after drinking alcohol (Ijiri, 1999). Facial flushing is the most obvious result of ALDH2 deficiency, but symptoms also include “headaches, nausea, dizziness, and cardiac palpitations after consumption of alcoholic beverages” (Chen et al., 2014).

Construct Design

The ALDH2*2 sequence was based off of ALDH2*1 (NCBI: NM_001204889.1), but modified to remove an internal PstI site. Compared to wild type ALDH2*1, the mutant ALDH2*2 contains a single G to A point mutation, which leads to a change in codon 487, where GAA (coding for glutamic acid) is mutated to AAA (coding for lysine) (Enomoto et al., 1991). The part was confirmed by PCR using the primers VF2 and VR, as well as sequencing by Tri-I Biotech.

PCR Check Results

PCR Check for BBa_K2539250 using the forward and reverse primers VF2 and VR. The expected PCR size of BBa_K2539250 (ALDH2*2 basic part) is around 1800 bp. Bands with the correct size are boxed in yellow.

MIT MAHE 2020

Summary

It is the mutant form of human mitochondrial aldehyde dehydrogenase. This gene is slow to convert acetaldehyde to acetate (which is a toxic intermediate) into acetate. Hence acetaldehyde accumulates and induces inflammation, which causes the skin to appear red after consumption of alcohol.

References

Chen CH, Ferreira JCB, Gross ER, Mochly-Rosen D. (2014). Targeting Aldehyde Dehydrogenase 2: New Therapeutic Opportunities. Physiol Rev. 94(1):1-34.

Enomoto N, Takada A, Date T. (1991). Genotyping of the aldehyde dehydrogenase 2 (ALDH2) gene using the polymerase chain reaction: evidence for single point mutation in the ALDH2 gene of ALDH2-deficiency. Gastroenterol Jpn. 26(4): 440–447.

Ijiri I. (1999). [Biological actions of acetaldehyde]. Nihon Hoigaku Zasshi. 53(3):285-95.

Xiao, Q., Weiner, H., & Crabb, D. W. (1996). The mutation in the mitochondrial aldehyde dehydrogenase (ALDH2) gene responsible for alcohol-induced flushing increases turnover of the enzyme tetramers in a dominant fashion. The Journal of clinical investigation, 98(9), 2027–2032. https://doi.org/10.1172/JCI119007

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BglII site found at 1247
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 305
  Illegal NgoMIV site found at 448
  Illegal NgoMIV site found at 961
  
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal BsaI.rc site found at 367
  Illegal SapI.rc site found at 864