Growth differentiation factor 2 (GDF2) also known as 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...

 (BMP)-9 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 GDF2 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...

. GDF2 belongs to the transforming growth factor beta superfamily

Transforming growth factor beta superfamily

The transforming growth factor beta superfamily is a large family of structurally related cell regulatory proteins that was named after its first member, TGF-β1, originally described in 1983....

.

Function

GDF2 has a role in inducing and maintaining the ability of embryonic basal forebrain

Basal forebrain

The basal forebrain is a collection of structures located ventrally to the striatum. It is considered to be the major cholinergic output of the central nervous system . It includes a group of structures that lie near the bottom of the front of the brain, including the nucleus basalis, diagonal band...

 cholinergic neuron

Neuron

A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...

s (BFCN) to respond to a neurotransmitter

Neurotransmitter

Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...

 called acetylcholine

Acetylcholine

The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...

; BFCN are important for the processes of learning

Learning

Learning is acquiring new or modifying existing knowledge, behaviors, skills, values, or preferences and may involve synthesizing different types of information. The ability to learn is possessed by humans, animals and some machines. Progress over time tends to follow learning curves.Human learning...

, memory

Memory

In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....

 and attention

Attention

Attention is the cognitive process of paying attention to one aspect of the environment while ignoring others. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience....

. GDF2 is also important for the maturation of BFCN. Another role of GDF2 has been recently suggested. GDF2 is a potent inducer of hepcidin

Hepcidin

Hepcidin is a peptide hormone produced by the liver. It was discovered in 2000, and appears to be the master regulator of iron homeostasis in humans and other mammals. In humans, HAMP is the gene that encodes for hepcidin.-Structure:...

 (a cationic peptide that has a antimicrobial

Antimicrobial

An anti-microbial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Antimicrobial drugs either kill microbes or prevent the growth of microbes...

 properties) in liver

Liver

The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

 cells (hepatocyte

Hepatocyte

A hepatocyte is a cell of the main tissue of the liver. Hepatocytes make up 70-80% of the liver's cytoplasmic mass.These cells are involved in:* Protein synthesis* Protein storage* Transformation of carbohydrates...

s) and can regulate iron metabolism. The physiological receptor of GDF2 is thought to be activin receptor-like kinase 1, ALK1 (also called ACVRL1), an endothelial-specific type I receptor of the TGF-beta receptor family.

GDF2 is one of the most potent BMPs to induce orthotopic bone formation in vivo. BMP3

Bone morphogenetic protein 3

Bone morphogenetic protein 3 is a protein that in humans is encoded by the BMP3 gene.The protein encoded by this gene is a member of the transforming growth factor beta superfamily. It, like other bone morphogenetic proteins is known for its ability to induce bone and cartilage development. It is...

, a blocker of most BMPs seems not to affect GDF2.