Interaction of scavenger receptor class B type I with peroxisomal targeting receptor Pex5p.

• Scavenger receptor class B type I (SR-BI) is an HDL receptor that mediates selective HDL lipid uptake. Peroxisomes play an important role in lipid metabolism and peroxisomal targeting signal type 1 (PTS1)-containing proteins are translocated to peroxisomes by the peroxisomal targeting import receptor, Pex5p. We have previously identified a PTS1 motif in the intracellular domain of rat SR-BI. Here, we examine the possible interaction between Pex5p and SR-BI. Expression of a Flag-tagged intracellular domain of SR-BI resulted in translocation to the peroxisome as demonstrated by double labeling with anti-Flag IgG and anti-catalase IgG analyzed by confocal microscopy. Immunoprecipitation experiments with anti-SR-BI antibody showed that Pex5p co-precipitated with SR-BI. However, when an antibody against Pex5p was used for immunoprecipitation, only the 57kDa, non-glycosylated form, of SR-BI co-precipitated. We conclude that the PTS1 domain of SR-BI is functional and can mediate peroxisomal interaction via Pex5p, in vitro.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinsk bioteknologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Medical Biotechnology (hsv//eng)

Keyword

Amino Acid Sequence

Animals

Antigens

CD36

chemistry

metabolism

Binding Sites

CHO Cells

COS Cells

Cercopithecus aethiops

Cricetinae

Cricetulus

Lipoproteins

HDL

metabolism

Membrane Proteins

Molecular Biology

Peroxisomes

metabolism

Protein Binding

Protein Structure

Tertiary

Rats

Receptors

Cytoplasmic and Nuclear

chemistry

metabolism

Receptors

Immunologic

Receptors

Lipoprotein

Receptors

Scavenger

Scavenger Receptors

Class B

Sequence Homology

Amino Acid

Structure-Activity Relationship

Publication and Content Type

ref (subject category)

art (subject category)