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AP4M1 adaptor related protein complex 4 subunit mu 1 [ Homo sapiens (human) ]

Gene ID: 9179, updated on 6-Jul-2026
Official Symbol
AP4M1provided by HGNC
Official Full Name
adaptor related protein complex 4 subunit mu 1provided by HGNC
Primary source
HGNC:HGNC:574
See related
Ensembl:ENSG00000221838 MIM:602296; AllianceGenome:HGNC:574
Gene type
protein coding
RefSeq status
REVIEWED
Organism
Homo sapiens
Lineage
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
Also known as
MU-4; CPSQ3; SPG50; MU-ARP2
Summary
This gene encodes a subunit of the heterotetrameric AP-4 complex. The encoded protein belongs to the adaptor complexes medium subunits family. This AP-4 complex is involved in the recognition and sorting of cargo proteins with tyrosine-based motifs from the trans-golgi network to the endosomal-lysosomal system. [provided by RefSeq, Jul 2008]
Expression
Ubiquitous expression in testis (RPKM 12.8), endometrium (RPKM 6.9) and 25 other tissues See more
Orthologs
all
Try the new Gene page
Try the new Transcripts and proteins table
See AP4M1 in Genome Data Viewer
Location:
7q22.1
Exon count:
18
Annotation release Status Assembly Chr Location
RS_2025_08 current GRCh38.p14 (GCF_000001405.40) 7 NC_000007.14 (100100794..100109039)
RS_2025_08 current T2T-CHM13v2.0 (GCF_009914755.1) 7 NC_060931.1 (101340639..101348885)
RS_2024_09 previous assembly GRCh37.p13 (GCF_000001405.25) 7 NC_000007.13 (99699266..99706662)

Chromosome 7 - NC_000007.14Genomic Context describing neighboring genes Neighboring gene H3K4me1 hESC enhancer GRCh37_chr7:99693124-99693624 Neighboring gene microRNA 106b Neighboring gene minichromosome maintenance complex component 7 Neighboring gene microRNA 93 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 26335 Neighboring gene ATAC-STARR-seq lymphoblastoid silent region 18415 Neighboring gene NANOG-H3K27ac-H3K4me1 hESC enhancer GRCh37_chr7:99698720-99699272 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 26336 Neighboring gene H3K4me1 hESC enhancer GRCh37_chr7:99704970-99705470 Neighboring gene ReSE screen-validated silencer GRCh37_chr7:99708249-99708476 Neighboring gene TATA-box binding protein associated factor 6 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 26337 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 26338 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 26339 Neighboring gene canopy FGF signaling regulator 4 Neighboring gene H3K4me1 hESC enhancer GRCh37_chr7:99723160-99723829 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 26340 Neighboring gene ATAC-STARR-seq lymphoblastoid silent region 18416 Neighboring gene ATAC-STARR-seq lymphoblastoid silent region 18417 Neighboring gene metallo-beta-lactamase domain containing 1

Go to nucleotide: Graphics FASTA GenBank

  • Project title: Tissue-specific circular RNA induction during human fetal development
  • Description: 35 human fetal samples from 6 tissues (3 - 7 replicates per tissue) collected between 10 and 20 weeks gestational time were sequenced using Illumina TruSeq Stranded Total RNA
  • BioProject: PRJNA270632
  • Publication: PMID 26076956
  • Analysis date: Mon Apr 2 22:54:59 2018

Related articles in PubMed

  1. A novel loss of function mutation in adaptor protein complex 4, subunit mu-1 causing autosomal recessive spastic paraplegia 50. Bellad A, et al. Neurol Sci, 2021 Dec. PMID 33884525
  2. A novel AP4M1 mutation in autosomal recessive cerebral palsy syndrome and clinical expansion of AP-4 deficiency. Jameel M, et al. BMC Med Genet, 2014 Dec 14. PMID 25496299, Free PMC Article
  3. Putative founder effect of Arg338* AP4M1 (SPG50) variant causing severe intellectual disability, epilepsy and spastic paraplegia: Report of three families. Becker A, et al. Clin Genet, 2023 Mar. PMID 36371792, Free PMC Article
  4. Identification of novel homozygous variants in FOXE3 and AP4M1 underlying congenital syndromic anophthalmia and microphthalmia. Akbar W, et al. J Gene Med, 2024 Jan. PMID 37758467
  5. Mutation in the AP4M1 gene provides a model for neuroaxonal injury in cerebral palsy. Verkerk AJ, et al. Am J Hum Genet, 2009 Jul. PMID 19559397, Free PMC Article

See all (54) citations in PubMed

GeneRIFs: Gene References Into Functions

What's a GeneRIF?
  1. Identification of novel homozygous variants in FOXE3 and AP4M1 underlying congenital syndromic anophthalmia and microphthalmia.
    Title: Identification of novel homozygous variants in FOXE3 and AP4M1 underlying congenital syndromic anophthalmia and microphthalmia.
  2. Putative founder effect of Arg338* AP4M1 (SPG50) variant causing severe intellectual disability, epilepsy and spastic paraplegia: Report of three families.
    Title: Putative founder effect of Arg338* AP4M1 (SPG50) variant causing severe intellectual disability, epilepsy and spastic paraplegia: Report of three families.
  3. A novel loss of function mutation in adaptor protein complex 4, subunit mu-1 causing autosomal recessive spastic paraplegia 50.
    Title: A novel loss of function mutation in adaptor protein complex 4, subunit mu-1 causing autosomal recessive spastic paraplegia 50.
  4. AP4M1 mutation is associated with hereditary spastic paraplegia.
    Title: Locus and allelic heterogeneity in five families with hereditary spastic paraplegia.
  5. Here, the authors demonstrate that dileucine motifs in the hepatitis C virus NS2 protein mediate AP-1A, AP-1B, and AP-4 binding and cell-free virus release. Moreover, they reveal that AP-4, an adaptor not previously implicated in viral infections, mediates cell-to-cell spread and hepatitis C virus trafficking.
    Title: Interactions between the Hepatitis C Virus Nonstructural 2 Protein and Host Adaptor Proteins 1 and 4 Orchestrate Virus Release.
  6. analysis of the AP4M1 mutation associated with aggressive behavior in addition to mild dysmorphic features, intellectual disability, spastic paraparesis and reduced head circumference [case report]
    Title: A novel AP4M1 mutation in autosomal recessive cerebral palsy syndrome and clinical expansion of AP-4 deficiency.
  7. In all five patients with autosomal-recessive type of tetraplegic cerebral palsy with mental retardation, a donor splice site pathogenic mutation in intron 14 of the AP4M1 gene (c.1137+1G-->T), was identified.
    Title: Mutation in the AP4M1 gene provides a model for neuroaxonal injury in cerebral palsy.
  8. AP-4 protein complex is involved in the regulation of somatodendritic-specific distribution of its cargo proteins including AMPA receptors.
    Title: Accumulation of AMPA receptors in autophagosomes in neuronal axons lacking adaptor protein AP-4.
  9. Results show that AP-4 can bind different types of cytosolic signals known to mediate basolateral transport in epithelial cells. Depletion of mu 4 results in the mis-sorting of several proteins in epithelial cells.
    Title: AP-4 binds basolateral signals and participates in basolateral sorting in epithelial MDCK cells.
Submit: New GeneRIF Correction

Review eQTL and phenotype association data in this region using PheGenI

Associated conditions

Description Tests
Hereditary spastic paraplegia 50
MedGen: C2752008 OMIM: 612936 GeneReviews: AP-4-Associated Hereditary Spastic Paraplegia
Compare labs

See variants in ClinVar

See studies and variants in dbVar

See Variation Viewer (GRCh37.p13)

Products Interactant Other Gene Complex Source Pubs Description

Markers

Homology

Gene Ontology Provided by GOA

Function Evidence Code Pubs
enables clathrin-cargo adaptor activity IBA
Inferred from Biological aspect of Ancestor
more info
  
enables protein binding IPI
Inferred from Physical Interaction
more info
 PubMed 
enables protein domain specific binding IDA
Inferred from Direct Assay
more info
 PubMed 
enables transmembrane protein transporter activity TAS
Traceable Author Statement
more info
  
Process Evidence Code Pubs
involved_in Golgi to endosome transport IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in Golgi to lysosome transport IBA
Inferred from Biological aspect of Ancestor
more info
  
involved_in Golgi to lysosome transport IDA
Inferred from Direct Assay
more info
 PubMed 
involved_in autophagosome assembly IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in intracellular protein localization IEA
Inferred from Electronic Annotation
more info
  
involved_in intracellular protein localization ISS
Inferred from Sequence or Structural Similarity
more info
  
involved_in intracellular protein transport IEA
Inferred from Electronic Annotation
more info
  
involved_in intracellular protein transport IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in post-Golgi vesicle-mediated transport TAS
Traceable Author Statement
more info
  
involved_in protein localization to basolateral plasma membrane ISS
Inferred from Sequence or Structural Similarity
more info
  
involved_in protein targeting IBA
Inferred from Biological aspect of Ancestor
more info
  
involved_in protein targeting IDA
Inferred from Direct Assay
more info
 PubMed 
involved_in protein targeting IEA
Inferred from Electronic Annotation
more info
  
involved_in protein targeting to lysosome IDA
Inferred from Direct Assay
more info
 PubMed 
involved_in protein transmembrane transport IEA
Inferred from Electronic Annotation
more info
  
involved_in vesicle-mediated transport IEA
Inferred from Electronic Annotation
more info
  
involved_in vesicle-mediated transport NAS
Non-traceable Author Statement
more info
 PubMed 
Component Evidence Code Pubs
part_of AP-4 adaptor complex IBA
Inferred from Biological aspect of Ancestor
more info
  
part_of AP-4 adaptor complex IDA
Inferred from Direct Assay
more info
 PubMed 
part_of AP-4 adaptor complex NAS
Non-traceable Author Statement
more info
 PubMed 
located_in Golgi apparatus IEA
Inferred from Electronic Annotation
more info
  
part_of clathrin adaptor complex IEA
Inferred from Electronic Annotation
more info
  
located_in cytosol IEA
Inferred from Electronic Annotation
more info
  
located_in early endosome EXP
Inferred from Experiment
more info
 PubMed 
located_in early endosome IEA
Inferred from Electronic Annotation
more info
  
located_in early endosome ISS
Inferred from Sequence or Structural Similarity
more info
  
located_in endosome lumen TAS
Traceable Author Statement
more info
  
located_in extracellular exosome HDA PubMed 
is_active_in trans-Golgi network IBA
Inferred from Biological aspect of Ancestor
more info
  
located_in trans-Golgi network IDA
Inferred from Direct Assay
more info
 PubMed 
part_of trans-Golgi network IDA
Inferred from Direct Assay
more info
 PubMed 
located_in trans-Golgi network NAS
Non-traceable Author Statement
more info
 PubMed 
located_in trans-Golgi network membrane TAS
Traceable Author Statement
more info
  
Preferred Names
AP-4 complex subunit mu-1
Names
AP-4 adaptor complex mu subunit
adapter-related protein complex 4 mu-1 subunit
adapter-related protein complex 4 subunit mu-1
adaptor related protein complex 4 mu 1 subunit
adaptor-related protein complex AP-4 mu4 subunit
mu subunit of AP-4
mu-adaptin-related protein-2
mu4
mu4-adaptin

NEW Try the new Transcript table

RefSeqs maintained independently of Annotated Genomes

These reference sequences exist independently of genome builds. Explain

These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

Genomic

  1. NG_016312.1 RefSeqGene

    Range
    5137..12533
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. NM_001363671.2 → NP_001350600.1  AP-4 complex subunit mu-1 isoform 2

    Status: REVIEWED

    Source sequence(s)
    AC073842
    Consensus CDS
    CCDS87527.1
    UniProtKB/TrEMBL
    A0ACI8VKW1, C9JC87
    Related
    ENSP00000403663.1, ENST00000429084.5
    Conserved Domains (2) summary
    cl02092
    Location:64 → 137
    Clat_adaptor_s; Clathrin adaptor complex small chain
    cd09253
    Location:182 → 460
    AP-4_Mu4_Cterm; C-terminal domain of medium Mu4 subunit in adaptor protein (AP) complex AP-4

  2. NM_001438824.1 → NP_001425753.1  AP-4 complex subunit mu-1 isoform 2

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/TrEMBL
    A0ACI8VKW1, C9JC87

  3. NM_001438825.1 → NP_001425754.1  AP-4 complex subunit mu-1 isoform 1

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/Swiss-Prot
    D6W5U1, O00189, Q8WV65, Q9UHK9
    UniProtKB/TrEMBL
    A0ACI8VKW1
    Related
    ENSP00000519097.1, ENST00000713791.1

  4. NM_001438826.1 → NP_001425755.1  AP-4 complex subunit mu-1 isoform 1

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/Swiss-Prot
    D6W5U1, O00189, Q8WV65, Q9UHK9
    UniProtKB/TrEMBL
    A0ACI8VKW1
    Related
    ENSP00000518888.1, ENST00000713591.1

  5. NM_001438827.1 → NP_001425756.1  AP-4 complex subunit mu-1 isoform 3

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/TrEMBL
    A0ACI8SYV2, A0ACI8VKW1
    Related
    ENSP00000589046.1, ENST00000918987.1

  6. NM_001438828.1 → NP_001425757.1  AP-4 complex subunit mu-1 isoform 4

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/TrEMBL
    A0ACI8VKW1, H7C0A0
    Related
    ENSP00000393723.2, ENST00000445295.2

  7. NM_001438829.1 → NP_001425758.1  AP-4 complex subunit mu-1 isoform 5

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/TrEMBL
    A0ACI8VKW6, C9JWL4
    Related
    ENSP00000401613.2, ENST00000438383.6

  8. NM_001438830.1 → NP_001425759.1  AP-4 complex subunit mu-1 isoform 6

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/TrEMBL
    A0ACI8VKW6

  9. NM_001438831.1 → NP_001425760.1  AP-4 complex subunit mu-1 isoform 7

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/TrEMBL
    A0ACI8VKW6
    Related
    ENST00000495154.2

  10. NM_001438832.1 → NP_001425761.1  AP-4 complex subunit mu-1 isoform 7

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/TrEMBL
    A0ACI8VKW6

  11. NM_001446029.1 → NP_001432958.1  AP-4 complex subunit mu-1 isoform 1

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/Swiss-Prot
    D6W5U1, O00189, Q8WV65, Q9UHK9
    UniProtKB/TrEMBL
    A0ACI8VKW1

  12. NM_001446030.1 → NP_001432959.1  AP-4 complex subunit mu-1 isoform 8

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/TrEMBL
    A0ACI8SFQ5, A0ACI8VKU2

  13. NM_001446031.1 → NP_001432960.1  AP-4 complex subunit mu-1 isoform 9

    Status: REVIEWED

    Source sequence(s)
    AC073842
    UniProtKB/TrEMBL
    A0AAQ5BH08, H7BZV3

  14. NM_004722.4 → NP_004713.2  AP-4 complex subunit mu-1 isoform 1

    See identical proteins and their annotated locations for NP_004713.2

    Status: REVIEWED

    Source sequence(s)
    AC073842, AF020796, BC012023, DC413622, Y08387
    Consensus CDS
    CCDS5685.1
    UniProtKB/Swiss-Prot
    D6W5U1, O00189, Q8WV65, Q9UHK9
    UniProtKB/TrEMBL
    A0ACI8VKW1
    Related
    ENSP00000352603.4, ENST00000359593.9
    Conserved Domains (2) summary
    cd09253
    Location:175 → 453
    AP-4_Mu4_Cterm; C-terminal domain of medium Mu4 subunit in adaptor protein (AP) complex AP-4
    cd14838
    Location:3 → 141
    AP4_Mu_N; AP-4 complex subunit mu N-terminal domain

RNA

  1. NR_199390.1 RNA Sequence

    Status: REVIEWED

    Source sequence(s)
    AC073842
    Related
    ENST00000713797.1

RefSeqs of Annotated Genomes: GCF_000001405.40-RS_2025_08

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

Reference GRCh38.p14 Primary Assembly

Genomic

  1. NC_000007.14 Reference GRCh38.p14 Primary Assembly

    Range
    100100794..100109039
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. XM_005250689.5 → XP_005250746.1  AP-4 complex subunit mu-1 isoform X1

    See identical proteins and their annotated locations for XP_005250746.1

    UniProtKB/TrEMBL
    A0ACI8VKW1, C9JC87
    Related
    ENSP00000589044.1, ENST00000918985.1
    Conserved Domains (2) summary
    cl02092
    Location:64 → 137
    Clat_adaptor_s; Clathrin adaptor complex small chain
    cd09253
    Location:182 → 460
    AP-4_Mu4_Cterm; C-terminal domain of medium Mu4 subunit in adaptor protein (AP) complex AP-4

Alternate T2T-CHM13v2.0

Genomic

  1. NC_060931.1 Alternate T2T-CHM13v2.0

    Range
    101340639..101348885
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. XM_054359317.1 → XP_054215292.1  AP-4 complex subunit mu-1 isoform X1

    UniProtKB/TrEMBL
    A0ACI8VKW1, C9JC87
Nucleotide Protein
Heading Accession and Version
Protein Accession Links
GenPept Link UniProtKB Link
O00189.2 GenPept UniProtKB/Swiss-Prot:O00189

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