Macrophage scavenger receptor 1, also known as MSR1, is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
which in humans is encoded by the ''MSR1''
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
MSR1 has also been designated CD204 (
cluster of differentiation
The cluster of differentiation (also known as cluster of designation or classification determinant and often abbreviated as CD) is a protocol used for the identification and investigation of cell surface molecules providing targets for immunophen ...
204).
Function
This gene encodes the class A
macrophage scavenger receptors, which include three different types (1, 2, 3) generated by alternative splicing of this gene. These receptors or isoforms are trimeric integral membrane
glycoproteins and have been implicated in many macrophage-associated physiological and pathological processes including atherosclerosis,
Alzheimer's disease, and host defense. They were thought to be expressed macrophage-specific, but recently shown to be present on different dendritic cells classes, too.
The isoforms type 1 and type 2 are functional receptors and are able to mediate the endocytosis of modified
low density lipoprotein
Low-density lipoprotein (LDL) is one of the five major groups of lipoprotein that transport all fat molecules around the body in extracellular water. These groups, from least dense to most dense, are chylomicrons (aka ULDL by the overall densit ...
s (LDLs). The isoform type 3 does not internalize modified LDL (acetyl-LDL) despite having the domain shown to mediate this function in the types 1 and 2 isoforms. It has an altered intracellular processing and is trapped within the
endoplasmic reticulum, making it unable to perform
endocytosis. The isoform type 3 can inhibit the function of isoforms type 1 and type 2 when co-expressed, indicating a dominant negative effect and suggesting a mechanism for regulation of scavenger receptor activity in macrophages.
Biotechnology application
Macrophage scavenger receptor has been shown to mediate adhesion of macrophages and other cell lines to tissue culture plastic.
Interactions
MSR1 has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with
HSPA1A
Heat shock 70 kDa protein 1, also termed Hsp72, is a protein that in humans is encoded by the ''HSPA1A'' gene. As a member of the heat shock protein 70 family and a chaperone protein, it facilitates the proper folding of newly translated and misfo ...
.
References
Further reading
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
{{Clusters of differentiation
Clusters of differentiation
Scavenger receptors