title: Characterization of HSCD5, a novel human stearoyl-CoA desaturase unique to primates.
abstract: Stearoyl-CoA desaturase (SCD) is an integral membrane protein of the endoplasmic reticulum (ER) that catalyzes the formation of monounsaturated fatty acids from saturated fatty acids. Recent studies suggest that SCD is a key regulator of energy metabolism and has implications in dislipidemia and obesity. Four SCD isoforms (SCD1-4) have been identified in mouse. In human, only one SCD isoform has been characterized so far. Here we report that the previously reported human ACOD4 gene encodes a distinct stearoyl-CoA desaturase, hSCD5. GenBank database mining revealed orthologues of hSCD5 in the primates, but not in the rodents. In transiently transfected 293 cells, hSCD5 co-localized with calnexin on ER membrane. Microsome fractions prepared from hSCD1 and hSCD5 transfected cells displayed similar delta 9 desaturase activity. Quantitative real-time RT-PCR analysis suggested that hSCD5 was abundantly expressed in adult brain and pancreas. These data suggested that hSCD5 plays a role distinct from that of hSCD1 during development and in normal physiological conditions.
authors.affiliation: Cardiovascular Division, Lilly Research Labs, Eli Lilly and Company, DC 0343, Indianapolis, IN 46285, USA. jjw@lilly.com
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Lan
authors.initials: L
authors.lastname: Yu
authors.forename: Robert E
authors.initials: RE
authors.lastname: Schmidt
authors.forename: Chen
authors.initials: C
authors.lastname: Su
authors.forename: Xiaodi
authors.initials: X
authors.lastname: Huang
authors.forename: Kenneth
authors.initials: K
authors.lastname: Gould
authors.forename: Guoqing
authors.initials: G
authors.lastname: Cao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D019143:Evolution, Molecular; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D010802:Phylogeny; D011323:Primates; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013230:Stearoyl-CoA Desaturase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D011994:Recombinant Proteins; D004247:DNA; C502659:SCD5 protein, human; D013230:Stearoyl-CoA Desaturase