Leucine rich repeat containing 37A is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

in humans that is encoded by the ''LRRC37A''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. The LRRC37 gene family has been expanded in the

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

of the simians through

segmental duplication Low copy repeats (LCRs), also known as segmental duplications (SDs), or duplicons, are DNA sequences present in multiple locations within a genome that share high levels of sequence identity. Repeats The repeats, or duplications, are typically 10� ...

s leading to new genes in

simian The simians, anthropoids, or higher primates are an infraorder (Simiiformes ) of primates containing all animals traditionally called monkeys and apes. More precisely, they consist of the parvorders New World monkey, Platyrrhini (New World mon ...

hominid The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic family of primates that includes eight extant species in four genera: '' Pongo'' (the Bornean, Sumatran and Tapanuli orangutan); '' Gorilla'' (the ...

and

human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

species. Most of these new genes belong to the ancestral LRRC37A-type. The

human genome The human genome is a complete set of nucleic acid sequences for humans, encoded as the DNA within each of the 23 distinct chromosomes in the cell nucleus. A small DNA molecule is found within individual Mitochondrial DNA, mitochondria. These ar ...

s contains at least 4 encoding gene

paralogs Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a speci ...

with 3 of the ancestral type: LRRC37A, LRRC37A2, LRRC37A3 and a new type of receptor shared between hominid species: LRRC37B. In the human

cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. It is the largest site of Neuron, neural integration in the central nervous system, and plays ...

, LRRC37B is selectively expressed in

pyramidal neurons Pyramidal cells, or pyramidal neurons, are a type of multipolar neuron found in areas of the brain including the cerebral cortex, the hippocampus, and the amygdala. Pyramidal cells are the primary excitation units of the mammalian prefrontal cort ...

at the level of the axon initial segment, which is not found in other nonhuman primate species (chimpanzees, macaques). It decreases there the excitability of the neurons, a feature specific to the human species compared to other mammalian species. It acts by binding to secreted FGF13A and SCN1B which leads to an inhibition of the voltage-gate sodium channels which generate the

action potential An action potential (also known as a nerve impulse or "spike" when in a neuron) is a series of quick changes in voltage across a cell membrane. An action potential occurs when the membrane potential of a specific Cell (biology), cell rapidly ri ...

References

Further reading