Ly6/neurotoxin 1 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 ...

in humans that is encoded by the ''LYNX1''

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 ...

Alternatively spliced Alternative splicing, or alternative RNA splicing, or differential splicing, is an alternative splicing process during gene expression that allows a single gene to code for multiple proteins. In this process, particular exons of a gene may be ...

variants encoding different isoforms have been identified.

Function

This gene encodes a member of the Ly-6/ neurotoxin gene family, a group of

lymphocyte A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic ad ...

antigens that attach to the cell surface by a

glycosylphosphatidylinositol Glycosylphosphatidylinositol (), or glycophosphatidylinositol, or GPI in short, is a phosphoglyceride that can be attached to the C-terminus of a protein during posttranslational modification. The resulting GPI-anchored proteins play key roles in ...

anchor and have a unique structure showing conserved 8-10 cysteine residues with a characteristic spacing pattern. Functional analysis indicates that this protein is not a ligand or neurotransmitter but has the capacity to enhance

nicotinic acetylcholine receptor Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral ner ...

function in the presence of acetylcholine. This gene may also play a role in the

pathogenesis Pathogenesis is the process by which a disease or disorder develops. It can include factors which contribute not only to the onset of the disease or disorder, but also to its progression and maintenance. The word comes from Greek πάθος ''pat ...

of psoriasis vulgaris. The LYNX1 gene codes for a protein (Lynx1) that binds to

acetylcholine receptor An acetylcholine receptor (abbreviated AChR) is an integral membrane protein that responds to the binding of acetylcholine, a neurotransmitter. Classification Like other transmembrane receptors, acetylcholine receptors are classified according ...

s in the brain. Lynx1 a member of the Ly6 superfamily of proteins that are capable of modulating neurotransmitter receptors.

Lynx1 and Visual Plasticity

Transgenic mice A genetically modified mouse or genetically engineered mouse model (GEMM) is a mouse (''Mus musculus'') that has had its genome altered through the use of genetic engineering techniques. Genetically modified mice are commonly used for research or ...

without Lynx1 expression do not have a normal

critical period In developmental psychology and developmental biology, a critical period is a maturational stage in the lifespan of an organism during which the nervous system is especially sensitive to certain environmental stimuli. If, for some reason, the org ...

neuroplasticity Neuroplasticity, also known as neural plasticity, or brain plasticity, is the ability of neural networks in the brain to change through growth and reorganization. It is when the brain is rewired to function in some way that differs from how it p ...

in the

visual cortex The visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus and ...

for development of ocular dominance columns. These mice show unusually rapid recovery from amblyopia in adulthood indicating a role in reduction of synaptic plasticity during the normal expression of Lynx1 in adult brain. Lynx1 reduces adult visual cortex plasticity by binding to

nicotinic acetylcholine receptors Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral ...

(NAchR) and diminishing acetylcholine signaling. After the developmental

and into adulthood, both Lynx1 mRNA and protein levels increase in the adult V1 and the

lateral geniculate nucleus In neuroanatomy, the lateral geniculate nucleus (LGN; also called the lateral geniculate body or lateral geniculate complex) is a structure in the thalamus and a key component of the mammalian visual pathway. It is a small, ovoid, ventral projec ...

(LGN). Lynx1 and nAChR mRNAs are co-expressed in the LGN, as well as in

parvalbumin Parvalbumin (PV) is a calcium-binding protein with low molecular weight (typically 9-11 kDa). In humans, it is encoded by the ''PVALB'' gene. It is not a member of the albumin family; it is named for its size (''parv-'', from Latin ''parvus'' smal ...

-positive GABAergic interneurons. After monocular deprivation during the

to induce amblyopia, Lynx1 knock-out rat models spontaneously recovered normal visual acuity by reopening the closed eye. Similarly, an infusion of

physostigmine Physostigmine (also known as eserine from ''éséré'', the West African name for the Calabar bean) is a highly toxic parasympathomimetic alkaloid, specifically, a reversible cholinesterase inhibitor. It occurs naturally in the Calabar bean and ...

to increase acetylcholine signaling prompted recovery from amblyopia in wild type mice Inhibition of Lynx1 may be a possible therapeutic mechanism to prolong

synaptic plasticity In neuroscience, synaptic plasticity is the ability of synapses to strengthen or weaken over time, in response to increases or decreases in their activity. Since memories are postulated to be represented by vastly interconnected neural circuit ...

of the visual cortex and improve binocular function of some amblyopes.

References

{{NLM content Genes on human chromosome 8

Function

Lynx1 and Visual Plasticity

See also

References