Semaphorin-3A
protein-coding gene in the species Homo sapiens
Semaphorin-3A is a protein that in humans is encoded by the SEMA3A gene.
Function
The SEMA3A gene is a member of the semaphorin family and encodes a protein with an Ig-like C2-type (immunoglobulin-like) domain, a PSI domain and a Sema domain. This secreted Semaphorin-3A protein can function as either a chemorepulsive agent, inhibiting axonal outgrowth, or as a chemoattractive agent, stimulating the growth of apical dendrites. In both cases, the protein is vital for normal neuronal pattern development.
Semaphorin-3A is secreted by neurons and surrounding tissue to guide migrating cells and axons in the developing nervous system. Axon pathfinding is the process by which neurons follow very precise paths, send out axons, and react to specific chemical environments to reach the correct endpoint. The guidance is critical for the precise formation of neurons and the surrounding vasculature. Guidance cues, such as Sema3A, induce the collapse and paralysis of neuronal growth cones during the development of the nervous system.
This guidance cue for axons of neurons is signaled through receptor complexes containing Neuropilin-1 (NRP1) and a co-receptor. One of the first identified intracellular messengers required for the growth cone-collapse induced by Sema3A is the CRMP protein called CRMP2.
The public source identifies “Semaphorin-3A” as protein-coding gene in the species Homo sapiens. This brief keeps that definition visible, then builds a research path around Semaphorin-3A, protein-coding and gene.
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Datasets, specimens, observations and peer-reviewed methods provide the appropriate test for the technical claims summarized here. The source revision retrieved here is dated Sep 9, 2026. The linked authority identifier is Q18035334. None of the 0 selected statements returned an explicit reference.
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This entry incorporates text from “Semaphorin-3A” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.