Sema2b Semaphorin 2b [Drosophila melanogaster (fruit fly)] - Gene

Summary

Official Symbol: Sema2bprovided by FlyBase
Official Full Name: Semaphorin 2bprovided by FlyBase
Primary source: FLYBASE:FBgn0264273
Locus tag: Dmel_CG33960
See related: AllianceGenome:FB:FBgn0264273
Gene type: protein coding
RefSeq status: REVIEWED
Organism: Drosophila melanogaster
Lineage: Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Hexapoda; Insecta; Pterygota; Neoptera; Endopterygota; Diptera; Brachycera; Muscomorpha; Ephydroidea; Drosophilidae; Drosophila; Sophophora
Also known as: CG30322; CG33960; CG4383; Dmel\CG33960; sema-2b; Sema-2b; sema2b; SemaIIB
Summary: Predicted to enable chemorepellent activity and semaphorin receptor binding activity. Involved in neuron development and regulation of cell-matrix adhesion. Predicted to be active in plasma membrane. Is expressed in adult head; antennal lobe; larval ventral nerve cord; and sensory neurons. Human ortholog(s) of this gene implicated in hypogonadotropic hypogonadism 16 with or without anosmia and progressive myoclonus epilepsy. Orthologous to several human genes including SEMA3A (semaphorin 3A); SEMA3B (semaphorin 3B); and SEMA3C (semaphorin 3C). [provided by Alliance of Genome Resources, Dec 2024]
Orthologs: all
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Genomic context

Location:: 53C4-53C4; 2-80 cM

Exon count:: 16

Annotation release	Status	Assembly	Chr	Location
Release 6.54	current	Release 6 plus ISO1 MT (GCF_000001215.4)	2R	NT_033778.4 (16386524..16431758)
Release 5.57	previous assembly	Release 5 (GCF_000001215.2)	2R	NT_033778.3 (12274029..12319263)

Chromosome 2R - NT_033778.4 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

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Go to reference sequence details

Genomic Sequence:

Go to nucleotide: Graphics FASTA GenBank

Bibliography

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GeneRIFs: Gene References Into Functions

What's a GeneRIF?

Secreted semaphorin 2b (Sema-2b) acts through its transmembrane receptor Plexin B (PlexB) to locally attract neural processes to specific fan-shaped body (FB) laminae. Aberrant Sema-2b/PlexB signaling leads to select disruptions in neural lamination, and these disruptions result in the formation of ectopic inhibitory connections between subsets of FB neurons.
Title: Semaphorin 2b Regulates Sleep-Circuit Formation in the Drosophila Central Brain.
semaphorin 2b is a target-derived signal that acts upon presynaptic plexin B receptors to mediate the retrograde, homeostatic control of presynaptic neurotransmitter release at the neuromuscular junction in Drosophila; Sema2b-PlexB signalling regulates presynaptic homeostatic plasticity through the cytoplasmic protein Mical and the oxoreductase-dependent control of presynaptic actin
Title: Retrograde semaphorin-plexin signalling drives homeostatic synaptic plasticity.
This study showed that mutations in the semaphorin ligand sema-2b lead to a dramatic increase in self-crossing of dendrites due to defects in dendrite-extracellular matrix adhesion.
Title: Epidermis-Derived Semaphorin Promotes Dendrite Self-Avoidance by Regulating Dendrite-Substrate Adhesion in Drosophila Sensory Neurons.
Sema-2b couples olfactory receptor neuron axon guidance to postsynaptic target neuron dendrite patterning well before the final target selection phase.
Title: Linking cell fate, trajectory choice, and target selection: genetic analysis of Sema-2b in olfactory axon targeting.

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Interactions

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Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

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Homology

NCBI Orthologs

Orthologs from OrthoDB

Gene Ontology Provided by FlyBase

Function	Evidence Code	Pubs
enables chemorepellent activity	IBA Inferred from Biological aspect of Ancestor more info
enables semaphorin receptor binding	IBA Inferred from Biological aspect of Ancestor more info
enables semaphorin receptor binding	IEA Inferred from Electronic Annotation more info

Process	Evidence Code	Pubs
involved_in axon guidance	IBA Inferred from Biological aspect of Ancestor more info
involved_in dendrite guidance	IGI Inferred from Genetic Interaction more info	PubMed
involved_in dendrite self-avoidance	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in negative chemotaxis	IBA Inferred from Biological aspect of Ancestor more info
involved_in olfactory bulb axon guidance	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in positive regulation of cell migration	IBA Inferred from Biological aspect of Ancestor more info
involved_in regulation of cell-matrix adhesion	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in semaphorin-plexin signaling pathway	IBA Inferred from Biological aspect of Ancestor more info
involved_in synaptic target attraction	IMP Inferred from Mutant Phenotype more info	PubMed

Component	Evidence Code	Pubs
is_active_in plasma membrane	IBA Inferred from Biological aspect of Ancestor more info

General protein information

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Preferred Names: semaphorin 2b

Names: CG33960-PA; CG33960-PB; CG33960-PC; CG33960-PD; Sema-2b; Sema2b-PA; Sema2b-PB; Sema2b-PC; Sema2b-PD; Semaphorin-2b; semaphorin; semaphorin2b; semiphorin

NCBI Reference Sequences (RefSeq)

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Genome Annotation

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference assembly

Genomic

NT_033778.4 Reference assembly

Range

16386524..16431758

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GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

NM_001274096.1 → NP_001261025.1 semaphorin 2b, isoform C [Drosophila melanogaster]

See identical proteins and their annotated locations for NP_001261025.1

Status: REVIEWED

UniProtKB/TrEMBL

A1ZAF5, Q5BI99

Conserved Domains (2) summary

cd11238
Location:120 → 578

Sema_2A; The Sema domain, a protein interacting module, of semaphorin 2A (Sema2A)

cl11960
Location:631 → 719

Ig; Immunoglobulin domain
NM_001144208.2 → NP_001137680.1 semaphorin 2b, isoform B [Drosophila melanogaster]

See identical proteins and their annotated locations for NP_001137680.1

Status: REVIEWED

UniProtKB/TrEMBL

Q29QV5, Q5BI99

Conserved Domains (2) summary

cd11238
Location:120 → 579

Sema_2A; The Sema domain, a protein interacting module, of semaphorin 2A (Sema2A)

cl11960
Location:632 → 720

Ig; Immunoglobulin domain
NM_001274095.1 → NP_001261024.1 semaphorin 2b, isoform D [Drosophila melanogaster]

See identical proteins and their annotated locations for NP_001261024.1

Status: REVIEWED

UniProtKB/TrEMBL

A0A0B4KG38, Q5BI99

Conserved Domains (2) summary

cd11238
Location:120 → 579

Sema_2A; The Sema domain, a protein interacting module, of semaphorin 2A (Sema2A)

cl11960
Location:632 → 720

Ig; Immunoglobulin domain
NM_001038863.4 → NP_001033952.1 semaphorin 2b, isoform A [Drosophila melanogaster]

See identical proteins and their annotated locations for NP_001033952.1

Status: REVIEWED

UniProtKB/TrEMBL

A1ZAF5, Q5BI99

Conserved Domains (2) summary

cd11238
Location:120 → 578

Sema_2A; The Sema domain, a protein interacting module, of semaphorin 2A (Sema2A)

cl11960
Location:631 → 719

Ig; Immunoglobulin domain