RNF130 Regulates LDLR Availability and Plasma LDL Cholesterol Levels.

Area of Science:

• Biochemistry
• Molecular Biology
• Genetics

Background:

• Liver-mediated removal of plasma low-density lipoprotein cholesterol (LDL-C) depends on efficient receptor-mediated endocytosis.
• Enhancing hepatic LDL receptor (LDLR) availability is a key strategy for lowering LDL-C.
• RNF130's role in regulating LDLR plasma membrane availability is newly described.

Purpose of the Study:

• To investigate the function of RNF130 in regulating LDL-C levels.
• To determine how RNF130 impacts the abundance and cellular localization of LDLR.
• To explore RNF130 as a potential therapeutic target for hypercholesterolemia.

Main Methods:

• In vivo and in vitro gain-of-function and loss-of-function experiments were conducted.
• RNF130 overexpression and nonfunctional mutants were used in vivo.
• In vitro ubiquitination assays and immunohistochemical staining assessed LDLR levels and distribution.
• Three distinct in vivo models (ASO, germline deletion, AAV CRISPR) were employed to disrupt RNF130.

Main Results:

• RNF130 functions as an E3 ubiquitin ligase, ubiquitinating LDLR and promoting its removal from the plasma membrane.
• Overexpression of RNF130 led to reduced hepatic LDLR and elevated plasma LDL-C.
• Disruption of RNF130 in vivo increased hepatic LDLR abundance and decreased plasma LDL-C.

Conclusions:

• RNF130 is identified as a novel post-translational regulator of plasma LDL-C levels.
• RNF130 modulates LDLR availability at the plasma membrane.
• Targeting RNF130 offers a potential strategy for managing hypercholesterolemia.