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The N‐terminal Regions of CYP1A Proteins Affect Their Microdomain Localization in the Endoplasmic Reticulum
Author(s) -
Park Ji Won,
Reed James,
Backes Wayne
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.778.1
Subject(s) - lipid microdomain , cyp1a2 , endoplasmic reticulum , polyproline helix , subcellular localization , biochemistry , chemistry , microbiology and biotechnology , biology , biophysics , peptide , membrane , cytoplasm , microsome , enzyme
Cell membranes are composed of numerous lipid species that distribute heterogeneously into microdomains having unique characteristics. Ordered domains are enriched in cholesterol, sphingomyelin and saturated phospholipids, which are not readily solubilized with non‐ionic detergent. Disordered domains contain higher levels of unsaturated fatty acids and are more readily disrupted. Previously, we showed that different P450s localized into specific microdomains. Interestingly, despite their high degree of sequence similarity, CYP1A1 and CYP1A2 resided in different membrane regions. Whereas CYP1A2 localized in ordered domains, CYP1A1 was exclusively found in disordered domains. The goal of this study was to identify the regions of CYP1A responsible for microdomain localization. To accomplish this goal, the localization of chimeric CYP1A1 and CYP1A2 was examined in HEK293T cells. CYP1A2 containing the N‐terminal region of CYP1A1, failed to localize in ordered domains, whereas CYP1A1, containing N‐terminal sequences of CYP1A2, gained the ability to localize into ordered regions even though it was not fully targeted to the regions. In addition, substitution of a peptide segment of CYP1A2 from 206 to 302 amino acids with the matched CYP1A1 sequences caused relocalization of intact CYP1A2 into disordered domains. In conclusion, these data demonstrate that N‐terminal regions of CYP1A2 play an essential role in targeting CYP1A2 to ordered domains, but internal sequences are also required for the proper localization of CYP1A2. Supported by R01 ES004344 and P42 ES013648.