title: Identification of cholesterol-regulating genes by targeted RNAi screening.
abstract: Elevated plasma cholesterol levels are considered responsible for excess cardiovascular morbidity and mortality. Cholesterol in plasma is tightly controlled by cholesterol within cells. Here, we developed and applied an integrative functional genomics strategy that allows systematic identification of regulators of cellular cholesterol levels. Candidate genes were identified by genome-wide gene-expression profiling of sterol-depleted cells and systematic literature queries. The role of these genes in cholesterol regulation was then tested by targeted siRNA knockdown experiments quantifying cellular cholesterol levels and the efficiency of low-density lipoprotein (LDL) uptake. With this strategy, 20 genes were identified as functional regulators of cellular cholesterol homeostasis. Of these, we describe TMEM97 as SREBP target gene that under sterol-depleted conditions localizes to endo-/lysosomal compartments and binds to LDL cholesterol transport-regulating protein Niemann-Pick C1 (NPC1). Taken together, TMEM97 and other factors described here are promising to yield further insights into how cells control cholesterol levels.
authors: Institute of Human Genetics, University of Heidelberg, Seminarstrasse 2, Heidelberg, Germany.
authors: Fabian
authors: F
authors: Bartz
authors: Luise
authors: L
authors: Kern
authors: Dorothee
authors: D
authors: Erz
authors: Mingang
authors: M
authors: Zhu
authors: Daniel
authors: D
authors: Gilbert
authors: Till
authors: T
authors: Meinhof
authors: Ute
authors: U
authors: Wirkner
authors: Holger
authors: H
authors: Erfle
authors: Martina
authors: M
authors: Muckenthaler
authors: Rainer
authors: R
authors: Pepperkok
authors: Heiko
authors: H
authors: Runz
mesh_terms: D045744:Cell Line, Tumor; D008078:Cholesterol, LDL / Q000097:blood / Q000378:metabolism*; D020869:Gene Expression Profiling; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D052556:Niemann-Pick Disease, Type C / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics / Q000378:metabolism
chemical_list: D008078:Cholesterol, LDL; D008565:Membrane Proteins; D034741:RNA, Small Interfering; C497387:SREBF1 protein, human; D051780:Sterol Regulatory Element Binding Protein 1; C516615:TMEM97 protein, human