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Hormone-sensitive lipase: sequence, expression, and chromosomal localization to 19 cent-q13.3
C Holm1, T G Kirchgessner, K L Svenson
1Department of Medical and Physiological Chemistry, University of Lund, Sweden.
Science (New York, N.Y.)
|September 16, 1988
Summary
Hormone-sensitive lipase (HSL) is a crucial enzyme for fat mobilization and energy balance. Researchers identified its unique structure, a key phosphorylation site, and its gene location, advancing our understanding of metabolic regulation.
Area of Science:
- Biochemistry
- Molecular Biology
- Genetics
Background:
- Hormone-sensitive lipase (HSL) plays a vital role in fatty acid mobilization, energy homeostasis, and potentially steroidogenesis.
- HSL activity is rapidly regulated by reversible phosphorylation, influenced by hormones like catecholamines and insulin.
Purpose of the Study:
- To characterize the molecular properties of hormone-sensitive lipase.
- To identify the enzyme's structure, phosphorylation sites, and gene location.
Main Methods:
- Cloning and sequencing of rat adipocyte complementary DNA to predict the amino acid sequence.
- Localization of the activity-controlling phosphorylation site.
- Identification of a potential lipid-binding consensus site.
- Analysis of messenger RNA (mRNA) expression in various tissues.
- Mapping of the human HSL gene.
Main Results:
- The predicted 757-amino acid sequence of HSL showed no homology to known lipases or proteins, indicating novelty.
- The activity-controlling phosphorylation site was identified at Serine 563 within a hydrophilic domain.
- A putative lipid-binding consensus site was tentatively identified.
- Multiple mRNA species (3.3, 3.5, or 3.9 kilobases) were detected in adipose, steroidogenic, heart, and skeletal muscle tissues.
- The human HSL gene was mapped to chromosome 19 cent-q13.3.
Conclusions:
- Hormone-sensitive lipase possesses a unique structure distinct from other lipases.
- The identification of Ser563 as the key phosphorylation site provides insight into its hormonal regulation.
- The tissue-specific expression and gene mapping contribute to understanding HSL's role in metabolism and disease.