Modulation of PICALM Levels Perturbs Cellular Cholesterol Homeostasis.

Published online

Journal Article

PICALM (Phosphatidyl Inositol Clathrin Assembly Lymphoid Myeloid protein) is a ubiquitously expressed protein that plays a role in clathrin-mediated endocytosis. PICALM also affects the internalization and trafficking of SNAREs and modulates macroautophagy. Chromosomal translocations that result in the fusion of PICALM to heterologous proteins cause leukemias, and genome-wide association studies have linked PICALM Single Nucleotide Polymorphisms (SNPs) to Alzheimer's disease. To obtain insight into the biological role of PICALM, we performed gene expression studies of PICALM-deficient and PICALM-expressing cells. Pathway analysis demonstrated that PICALM expression influences the expression of genes that encode proteins involved in cholesterol biosynthesis and lipoprotein uptake. Gas Chromatography-Mass Spectrometry (GC-MS) studies indicated that loss of PICALM increases cellular cholesterol pool size. Isotopic labeling studies revealed that loss of PICALM alters increased net scavenging of cholesterol. Flow cytometry analyses confirmed that internalization of the LDL receptor is enhanced in PICALM-deficient cells as a result of higher levels of LDLR expression. These findings suggest that PICALM is required for cellular cholesterol homeostasis and point to a novel mechanism by which PICALM alterations may contribute to disease.

Full Text

Duke Authors

Cited Authors

  • Mercer, JL; Argus, JP; Crabtree, DM; Keenan, MM; Wilks, MQ; Chi, J-TA; Bensinger, SJ; Lavau, CP; Wechsler, DS

Published Date

  • 2015

Published In

Volume / Issue

  • 10 / 6

Start / End Page

  • e0129776 -

PubMed ID

  • 26075887

Pubmed Central ID

  • 26075887

Electronic International Standard Serial Number (EISSN)

  • 1932-6203

Digital Object Identifier (DOI)

  • 10.1371/journal.pone.0129776

Language

  • eng

Conference Location

  • United States