Document Type
Article
Publication Date
10-22-2024
Publication Title
Journal of Biological Chemistry
Abstract
The endoplasmic reticulum is organized into ordered regions enriched in cholesterol and sphingomyelin, and disordered microdomains characterized by more fluidity. Rabbit CYP1A1 and CYP1A2 localize into disordered and ordered microdomains, respectively. Previously, a CYP1A2 chimera containing the first 109 amino acids of CYP1A1 showed altered microdomain localization. The goal of this study was to identify specific residues responsible for CYP1A microdomain localization. Thus, CYP1A2 chimeras containing substitutions from homologous regions of CYP1A1 were expressed in HEK 293T/17 cells, and the localization was examined after solubilization with Brij 98. A CYP1A2 mutant with the three amino acids from CYP1A1 (VAG) at positions 27 to 29 of CYP1A2 was generated that showed a distribution pattern similar to those of CYP1A1/1A2 chimeras containing both the first 109 amino acids and the first 31 amino acids of CYP1A1 followed by remaining amino acids of CYP1A2. Similarly, the reciprocal substitution of three amino acids from CYP1A2 (AVR) into CYP1A1 resulted in a partial redistribution of the chimera into ordered microdomains. Molecular dynamic simulations indicate that the positive charges of the CYP1A1 and CYP1A2 linker regions between the N termini and catalytic domains resulted in different depths of immersion of the N termini in the membrane. The overlap of the distribution of positively charged residues in CYP1A2 (AVR) and negatively charged phospholipids was higher in the ordered than in the disordered microdomain. These findings identify three residues in the CYP1AN terminus as a novel microdomain-targeting motif of the P450s and provide a mechanistic explanation for the differential microdomain localization of CYP1A.
PubMed ID
39447873
Volume
300
Issue
11
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Fuchs, Robert M.; Reed, James R.; Connick, J. Patrick; Paloncýová, Markéta; Šrejber, Martin; Čechová, Petra; Otyepka, Michal; Eyer, Marilyn K.; and Backes, Wayne L., "Identification of the N-terminal residues responsible for the differential microdomain localization of CYP1A1 and CYP1A2" (2024). School of Graduate Studies Faculty Publications. 342.
https://digitalscholar.lsuhsc.edu/sogs_facpubs/342
10.1016/j.jbc.2024.107891
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