Repulsive guidance molecule A also known as RGMa is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 that in humans is encoded by the RGMA gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

.

Function

RGMa is a repulsive guidance molecule

Repulsive guidance molecule

Repulsive Guidance Molecules are members of a three gene family composed of RGMa, RGMb, and RGMc ....

 for retinal axons. Furthermore neogenin

NEO1

Neogenin is a protein that in humans is encoded by the NEO1 gene.-Further reading:...

 functions as a receptor for RGM. Neogenin overexpression and RGM downexpression in the developing embryonic neural tube

Neural tube

In the developing vertebrate, the neural tube is the embryo's precursor to the central nervous system, which comprises the brain and spinal cord...

 induces apoptosis

Apoptosis

Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...

. The apoptotic activity of neogenin in the neural tube is associated with cleavage of its cytoplasmic domain by caspase

Caspase

Caspases, or cysteine-aspartic proteases or cysteine-dependent aspartate-directed proteases are a family of cysteine proteases that play essential roles in apoptosis , necrosis, and inflammation....

s.

RGMA belongs to a family of repulsive guidance molecules that are (glycosylphosphatidylinositol)-linked cell-membrane-associated proteins. The three proteins, RGMa (this protein), RGMb

RGMB

RGM domain family, member B, also known as RGMB, is a protein that in humans is encoded by the RGMB gene.- Function :RGMB is a glycosylphosphatidylinositol -anchored member of the repulsive guidance molecule family and contributes to the patterning of the developing nervous system...

 and RGMc

Hemojuvelin

Hemojuvelin is a membrane-bound and soluble protein in mammals that is responsible for the iron overload condition known as juvenile hemochromatosis in humans, a severe form of hemochromatosis. In humans, the hemojuvelin protein is encoded by the HFE2 gene...

 are 40-50% identical to each other, and share similarities in predicted protein domains and overall structure. All three RGM proteins appear capable of binding selected BMPs (bone morphogenetic protein

Bone morphogenetic protein

Bone morphogenetic proteins are a group of growth factors also known as cytokines and as metabologens . Originally discovered by their ability to induce the formation of bone and cartilage, BMPs are now considered to constitute a group of pivotal morphogenetic signals, orchestrating tissue...

s)..

The RGMa homologue RGMc/HJV

Hemojuvelin

Hemojuvelin is a membrane-bound and soluble protein in mammals that is responsible for the iron overload condition known as juvenile hemochromatosis in humans, a severe form of hemochromatosis. In humans, the hemojuvelin protein is encoded by the HFE2 gene...

, is transcriptionally regulated during muscle differentiation.

Further reading