Mannose-6-phosphate receptor binding protein 1 (M6PRBP1) 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, respon ...
which in humans is encoded by the ''M6PRBP1''
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 ...
.
Its gene product, as well as the gene itself, is commonly known as TIP47.
Function
Mannose 6-phosphate receptor
The mannose 6-phosphate receptors (MPRs) are transmembrane glycoproteins that target enzymes to lysosomes in vertebrates.
Mannose 6-phosphate receptors bind newly synthesized lysosomal hydrolases in the trans-Golgi network (TGN) and deliver th ...
s (MPRs) deliver
lysosomal
A lysosome () is a membrane-bound organelle found in many animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane pr ...
hydrolase
Hydrolase is a class of enzyme that commonly perform as biochemical catalysts that use water to break a chemical bond, which typically results in dividing a larger molecule into smaller molecules. Some common examples of hydrolase enzymes are es ...
from the
Golgi Golgi may refer to:
*Camillo Golgi (1843–1926), Italian physician and scientist after whom the following terms are named:
**Golgi apparatus (also called the Golgi body, Golgi complex, or dictyosome), an organelle in a eukaryotic cell
**Golgi tend ...
to
endosome
Endosomes are a collection of intracellular sorting organelles in eukaryotic cells. They are parts of endocytic membrane transport pathway originating from the trans Golgi network. Molecules or ligands internalized from the plasma membrane c ...
s and then return to the Golgi complex. The protein encoded by this gene interacts with the cytoplasmic domains of both cation-independent and cation-dependent MPRs, and is required for endosome-to-Golgi transport. This protein also binds directly to the GTPase RAB9 (
RAB9A
Ras-related protein Rab-9A is a protein that in humans is encoded by the ''RAB9A'' gene.
Interactions
RAB9A has been shown to interact with RABEPK, TIP47
Mannose-6-phosphate receptor binding protein 1 (M6PRBP1) is a protein which in humans ...
), a member of the
RAS oncogene
Ras, from "Rat sarcoma virus", is a family of related proteins that are expressed in all animal cell lineages and organs. All Ras protein family members belong to a class of protein called small GTPase, and are involved in transmitting signals ...
family. The interaction with RAB9 has been shown to increase the affinity of this protein for its cargo.
The mannose-6-phosphate receptor-binding properties of TIP47 are disputed,
despite the designation of M6PRBP1 as TIP47's gene symbol. TIP47 protein is most commonly described in the scientific literature as a coat protein for
lipid
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids incl ...
droplets.
TIP47 belongs to the
peripilin protein family and shares significant homology with the other genes of this family, including
perilipin
Perilipin, also known as lipid droplet-associated protein, Perilipin 1, or PLIN, is a protein that, in humans, is encoded by the ''PLIN'' gene. The perilipins are a family of proteins that associate with the surface of lipid droplets. Phosphoryla ...
and
adipophilin
Adipose differentiation-related protein, also known as perilipin 2 , ADRP or adipophilin, is a protein which belongs from PAT family of cytoplasmic lipid droplet(CLD) binding protein. In humans it is encoded by the ''ADFP'' gene. This protein su ...
.
Interactions
M6PRBP1 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 organizat ...
with both
Mannose 6-phosphate receptor
The mannose 6-phosphate receptors (MPRs) are transmembrane glycoproteins that target enzymes to lysosomes in vertebrates.
Mannose 6-phosphate receptors bind newly synthesized lysosomal hydrolases in the trans-Golgi network (TGN) and deliver th ...
s.
References
Further reading
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
External links
*
*
{{Vesicular transport proteins