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Role of AIG1 and ADTRP in Endogenous FAHFA Regulation
Author(s) -
Ertunc Meric Erikci,
Kok Bernard P.,
Parsons William H.,
Wang Justin G.,
Tan Dan,
Donaldson Cynthia J.,
Pinto Antonio M.,
Vaughan Joan M.,
Ngo Nhi,
Lum Kenneth M.,
Henry Cassandra L.,
Coppola Aundrea R.,
Niphakis Micah J.,
Cravatt Benjamin F.,
Saez Enrique,
Saghatelian Alan
Publication year - 2020
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.2020.34.s1.04337
Subject(s) - enzyme , adipose tissue , endogeny , in vivo , knockout mouse , biochemistry , lipid signaling , biology , chemistry , gene , microbiology and biotechnology
Androgen‐induced gene 1 (AIG1) and Androgen‐dependent TFPI‐regulating protein (ADTRP) are atypical transmembrane hydrolases that rely on a catalytic threonine for their enzymatic activity. In vitro characterization of AIG1 and ADTRP in lysates and cells identified fatty acid ester of hydroxy fatty acids (FAHFAs) as their putative substrates. Here, we generate ADTRP knockout ( Adtrp ‐KO), AIG1 knockout ( Aig1‐ KO), and ADTRP/AIG1 double deficient (DKO) mice using CRISPR‐Cas9 technology to test whether these enzymes regulate FAHFAs in vivo . AIG1, ADTRP, or a deficiency in both enzymes leads to decreased FAHFA hydrolytic activity in tissue lysates. Quantitative measurement of FAHFA levels in several tissues revealed increased FAHFA levels in brown adipose tissue (BAT), subcutaneous adipose tissue (SQWAT), and perigonadal WAT (PGWAT) of Adtrp‐ KO mice consistent with the loss of FAHFA degrading activity. Furthermore, contribution by AIG1 was modest and only observed in the kidney and BAT of DKO mice. Lipidomics of tissues from knockout and wild type control mice detected no significant changes in other lipid classes to indicate that these enzymes are specific for FAHFA substrates. Furthermore, we developed a potent and selective, dual AIG1/ADTRP inhibitor to enable pharmacological interrogation of these enzymes in vivo . Chemical inhibition of AIG1 and ADTRP raised FAHFA levels demonstrating acute regulation of FAHFAs. In aggregate, the results establish AIG1 and ADTRP as the only endogenous FAHFA hydrolases known, and describe resources (mice, inhibitors) needed to elucidate the biochemical and physiological role of these exciting enzymes. Support or Funding Information This research was supported by the NIH (DK106210, DK114785, DA033760), The Leona M. and Harry B. Helmsley Charitable Trust (grant #2012‐PG‐MED002 to A.S.), NCI Cancer Center Support Grant P30 (CA014195 MASS core, A.S.), Dr. Frederick Paulsen Chair/Ferring Pharmaceuticals (A.S.), a NIH F32 postdoctoral fellowship, DK111159 (M.EE.), a Hewitt Foundation for Medical Research Fellowship (W.H.P.), Mass Spectrometry Core of the Salk Institute with funding from NIH‐NCI CCSG: P30 014195, NIH 1S10OD021815‐01 and the Helmsley Center for Genomic Medicine, and Transgenic Core Facility of the Salk Institute with funding from NIH‐NCI CCSG: P30 014195.