Cloning and characterization of a hormonally regulated rat long chain acyl-CoA synthetase

doi:10.1073/pnas.121046998

Cloning and characterization of a hormonally regulated rat long chain acyl-CoA synthetase

Section of Molecular Endocrinology, Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892

Edited by Maria Iandolo New, Weill Medical College of Cornell University, New York, NY, and approved April 3, 2001 (received for review January 29, 2001)

Abstract

A previously unidentified gonadotropin-regulated long chain acyl-CoA synthetase (GR-LACS) was cloned and characterized as a 79-kDa cytoplasmic protein expressed in Leydig cells of the rat testis. GR-LACS shares sequence identity with two conserved regions of the LACS and luciferase families, including the ATP/AMP binding domain and the 25-aa fatty acyl-CoA synthetase signature motif, but displays low overall amino acid similarities (23–28%). GR-LACS mRNA is expressed abundantly in Leydig cells of the adult testis and to a lesser degree in the seminiferous tubules in spermatogonia and Sertoli cells. It is also observed in ovary and brain. Immunoreactive protein expression was observed mainly in Leydig cells and minimally in the tubules but was not detected in other tissues. In vivo, treatment with a desensitizing dose of human chorionic gonadotropin caused transcriptional down-regulation of GR-LACS expression in Leydig cells. The expressed protein present in the cytoplasm of transfected cells displayed acyl-CoA synthetase activity for long chain fatty acid substrates. GR-LACS may contribute to the provision of energy requirements and to the biosynthesis of steroid precursors and could participate through acyl-CoA's multiple functions in the regulation of the male gonad.

Footnotes

↵ * P.-Z.T. and C.-H.T.-M. contributed equally to this work.
↵ † To whom reprint requests should be addressed at: Building 49, Room 6A36, National Institutes of Health, Bethesda, MD 20892-4510. E-mail: dufau{at}helix.nih.gov.
This paper was submitted directly (Track II) to the PNAS office.
Data deposition: The sequence reported in this paper has been deposited in the GenBank database (accession no. AF208125).
Abbreviations:

LH,

luteinizing hormone;

FACS,

fatty acyl-CoA synthetase;

hCG,

human chorionic gonadotropin;

GR-LACS,

gonadotropin-regulated long chain acyl-CoA synthetase;

GFP,

green fluorescent protein;

mLTC,

mouse Leydig tumor cells