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Aliases for SPG21 Gene

Aliases for SPG21 Gene

  • Spastic Paraplegia 21 (Autosomal Recessive, Mast Syndrome) 2 3 5
  • Acid Cluster Protein 33 3 4
  • ACP33 3 4
  • Spastic Paraplegia 21 Autosomal Recessive Mast Syndrome Protein 4
  • Spastic Paraplegia 21 Protein 4
  • Maspardin 2
  • BM-019 3
  • GL010 3
  • Mast 3

External Ids for SPG21 Gene

Previous GeneCards Identifiers for SPG21 Gene

  • GC13U900001
  • GC15M062972
  • GC15M063042
  • GC15M065255
  • GC15M042080

Summaries for SPG21 Gene

Entrez Gene Summary for SPG21 Gene

  • The protein encoded by this gene binds to the hydrophobic C-terminal amino acids of CD4 which are involved in repression of T cell activation. The interaction with CD4 is mediated by the noncatalytic alpha/beta hydrolase fold domain of this protein. It is thus proposed that this gene product modulates the stimulatory activity of CD4. Mutations in this gene are associated with autosomal recessive spastic paraplegia 21 (SPG21), also known as mast syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2014]

GeneCards Summary for SPG21 Gene

SPG21 (Spastic Paraplegia 21 (Autosomal Recessive, Mast Syndrome)) is a Protein Coding gene. Diseases associated with SPG21 include Mast Syndrome and Paraplegia. Among its related pathways are Endocytosis. GO annotations related to this gene include CD4 receptor binding.

UniProtKB/Swiss-Prot for SPG21 Gene

  • May play a role as a negative regulatory factor in CD4-dependent T-cell activation.

Gene Wiki entry for SPG21 Gene

No data available for Tocris Summary , PharmGKB "VIP" Summary , fRNAdb sequence ontologies and piRNA Summary for SPG21 Gene

Genomics for SPG21 Gene

Regulatory Elements for SPG21 Gene

Enhancers for SPG21 Gene
GeneHancer Identifier Score Enhancer Sources TSS distance (kb) Number of Genes Away Size (kb) Transcription Factor Binding Sites within enhancer Other Gene Targets for Enhancer

Enhancers around SPG21 on UCSC Golden Path with GeneCards custom track

Promoters for SPG21 Gene
Ensembl Regulatory Elements (ENSRs) TSS Distance (bp) Size (bp) Binding Sites for Transcription Factors within promoters

ENSRs around SPG21 on UCSC Golden Path with GeneCards custom track

Genomic Location for SPG21 Gene

64,963,021 bp from pter
64,990,310 bp from pter
27,290 bases
Minus strand

Genomic View for SPG21 Gene

Genes around SPG21 on UCSC Golden Path with GeneCards custom track

Cytogenetic band:
SPG21 Gene in genomic location: bands according to Ensembl, locations according to GeneLoc (and/or Entrez Gene and/or Ensembl if different)
Genomic Location for SPG21 Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

RefSeq DNA sequence for SPG21 Gene

Proteins for SPG21 Gene

  • Protein details for SPG21 Gene (UniProtKB/Swiss-Prot)

    Protein Symbol:
    Recommended name:
    Protein Accession:
    Secondary Accessions:
    • B4DW44
    • Q6ZMB6

    Protein attributes for SPG21 Gene

    308 amino acids
    Molecular mass:
    34960 Da
    Quaternary structure:
    • Interacts with CD4. Interacts with ALDH16A1.

    Alternative splice isoforms for SPG21 Gene


neXtProt entry for SPG21 Gene

Proteomics data for SPG21 Gene at MOPED

Post-translational modifications for SPG21 Gene

  • Modification sites at PhosphoSitePlus
  • Modification sites at neXtProt

No data available for DME Specific Peptides for SPG21 Gene

Domains & Families for SPG21 Gene

Protein Domains for SPG21 Gene

Suggested Antigen Peptide Sequences for SPG21 Gene

GenScript: Design optimal peptide antigens:

Graphical View of Domain Structure for InterPro Entry



  • Belongs to the AB hydrolase superfamily.
  • Belongs to the AB hydrolase superfamily.
genes like me logo Genes that share domains with SPG21: view

No data available for Gene Families for SPG21 Gene

Function for SPG21 Gene

Molecular function for SPG21 Gene

UniProtKB/Swiss-Prot Function:
May play a role as a negative regulatory factor in CD4-dependent T-cell activation.
genes like me logo Genes that share phenotypes with SPG21: view

Human Phenotype Ontology for SPG21 Gene

HPO Id HPO Name Alternative Ids Definition Synonyms

Animal Model Products

miRNA for SPG21 Gene

miRTarBase miRNAs that target SPG21

No data available for Enzyme Numbers (IUBMB) , Gene Ontology (GO) - Molecular Function , Animal Models , Transcription Factor Targets and HOMER Transcription for SPG21 Gene

Localization for SPG21 Gene

Subcellular locations from UniProtKB/Swiss-Prot for SPG21 Gene

Cytoplasm, cytosol. Membrane; Peripheral membrane protein. Endosome membrane; Peripheral membrane protein. Golgi apparatus, trans-Golgi network membrane; Peripheral membrane protein. Note=Partially localized in the cytosol but also accumulated on an intracellular vesicular compartment. Colocalizes with CD4 on endosomal/trans-Golgi network.

Subcellular locations from

Jensen Localization Image for SPG21 Gene COMPARTMENTS Subcellular localization image for SPG21 gene
Compartment Confidence
cytosol 5
golgi apparatus 5
endosome 3
nucleus 3
mitochondrion 2
cytoskeleton 1

Gene Ontology (GO) - Cellular Components for SPG21 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005737 cytoplasm IDA --
GO:0010008 endosome membrane IEA --
genes like me logo Genes that share ontologies with SPG21: view

Pathways & Interactions for SPG21 Gene

SuperPathways for SPG21 Gene

Superpath Contained pathways
1 Endocytosis
genes like me logo Genes that share pathways with SPG21: view

Pathways by source for SPG21 Gene

1 KEGG pathway for SPG21 Gene

Gene Ontology (GO) - Biological Process for SPG21 Gene


No data available for SIGNOR curated interactions for SPG21 Gene

Drugs & Compounds for SPG21 Gene

No Compound Related Data Available

Transcripts for SPG21 Gene

Unigene Clusters for SPG21 Gene

Spastic paraplegia 21 (autosomal recessive, Mast syndrome):
Representative Sequences:

Alternative Splicing Database (ASD) splice patterns (SP) for SPG21 Gene

ExUns: 1a · 1b ^ 2a · 2b ^ 3a · 3b ^ 4 ^ 5 ^ 6 ^ 7a · 7b · 7c ^ 8 ^ 9a · 9b ^ 10 ^ 11 ^ 12 ^ 13
SP1: - - - - - - -
SP2: - - - - -
SP3: - - -
SP5: - - - - - - - -
SP6: - - - - -

Relevant External Links for SPG21 Gene

GeneLoc Exon Structure for
ECgene alternative splicing isoforms for

Expression for SPG21 Gene

mRNA expression in normal human tissues for SPG21 Gene

mRNA expression in embryonic tissues and stem cells from LifeMap Discovery

Protein differential expression in normal tissues from HIPED for SPG21 Gene

This gene is overexpressed in Bone (18.3), Monocytes (7.5), and Peripheral blood mononuclear cells (6.7).

Integrated Proteomics: protein expression in normal tissues and cell lines from ProteomicsDB, PaxDb, MOPED, and MaxQB for SPG21 Gene

SOURCE GeneReport for Unigene cluster for SPG21 Gene Hs.242458

mRNA Expression by UniProt/SwissProt for SPG21 Gene

Tissue specificity: Expressed in all tissues tested, including heart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas. Expressed in J.CaM1.6, HuT 78 and HeLa cell lines (at protein level).
genes like me logo Genes that share expression patterns with SPG21: view

Protein tissue co-expression partners for SPG21 Gene

- Elite partner

Primer Products

No data available for mRNA differential expression in normal tissues for SPG21 Gene

Orthologs for SPG21 Gene

This gene was present in the common ancestor of eukaryotes.

Orthologs for SPG21 Gene

Organism Taxonomy Gene Similarity Type Details
(Bos Taurus)
Mammalia SPG21 35
  • 93.4 (n)
  • 98.7 (a)
SPG21 36
  • 99 (a)
(Canis familiaris)
Mammalia SPG21 35
  • 92.64 (n)
  • 98.7 (a)
SPG21 36
  • 99 (a)
(Mus musculus)
Mammalia Spg21 35
  • 88.06 (n)
  • 98.05 (a)
Spg21 16
Spg21 36
  • 98 (a)
(Pan troglodytes)
Mammalia SPG21 35
  • 99.78 (n)
  • 100 (a)
SPG21 36
  • 100 (a)
(Rattus norvegicus)
Mammalia Spg21 35
  • 89.36 (n)
  • 96.92 (a)
(Monodelphis domestica)
Mammalia SPG21 36
  • 97 (a)
(Ornithorhynchus anatinus)
Mammalia SPG21 36
  • 96 (a)
(Gallus gallus)
Aves SPG21 35
  • 82.36 (n)
  • 94.81 (a)
SPG21 36
  • 93 (a)
(Anolis carolinensis)
Reptilia SPG21 36
  • 90 (a)
tropical clawed frog
(Silurana tropicalis)
Amphibia spg21 35
  • 77.92 (n)
  • 89.61 (a)
Str.18797 35
(Danio rerio)
Actinopterygii Dr.27161 35
spg21 35
  • 75.65 (n)
  • 87.66 (a)
spg21 36
  • 87 (a)
SPG21 (2 of 2) 36
  • 87 (a)
rainbow trout
(Oncorhynchus mykiss)
Actinopterygii Omy.627 35
thale cress
(Arabidopsis thaliana)
eudicotyledons AT4G12230 35
  • 53.38 (n)
  • 45.86 (a)
(Oryza sativa)
Liliopsida Os10g0169800 35
  • 51.81 (n)
  • 44.96 (a)
sea squirt
(Ciona savignyi)
Ascidiacea -- 36
  • 45 (a)
Species with no ortholog for SPG21:
  • A. gosspyii yeast (Ashbya gossypii)
  • Actinobacteria (Mycobacterium tuberculosis)
  • African clawed frog (Xenopus laevis)
  • African malaria mosquito (Anopheles gambiae)
  • Alicante grape (Vitis vinifera)
  • alpha proteobacteria (Wolbachia pipientis)
  • amoeba (Dictyostelium discoideum)
  • Archea (Pyrococcus horikoshii)
  • baker's yeast (Saccharomyces cerevisiae)
  • barley (Hordeum vulgare)
  • beta proteobacteria (Neisseria meningitidis)
  • bread mold (Neurospora crassa)
  • Chromalveolata (Phytophthora infestans)
  • common water flea (Daphnia pulex)
  • corn (Zea mays)
  • E. coli (Escherichia coli)
  • filamentous fungi (Aspergillus nidulans)
  • Firmicute bacteria (Streptococcus pneumoniae)
  • fission yeast (Schizosaccharomyces pombe)
  • fruit fly (Drosophila melanogaster)
  • green algae (Chlamydomonas reinhardtii)
  • honey bee (Apis mellifera)
  • K. lactis yeast (Kluyveromyces lactis)
  • loblloly pine (Pinus taeda)
  • malaria parasite (Plasmodium falciparum)
  • medicago trunc (Medicago Truncatula)
  • moss (Physcomitrella patens)
  • orangutan (Pongo pygmaeus)
  • pig (Sus scrofa)
  • rice blast fungus (Magnaporthe grisea)
  • schistosome parasite (Schistosoma mansoni)
  • sea anemone (Nematostella vectensis)
  • sea urchin (Strongylocentrotus purpuratus)
  • sorghum (Sorghum bicolor)
  • soybean (Glycine max)
  • stem rust fungus (Puccinia graminis)
  • sugarcane (Saccharum officinarum)
  • tomato (Lycopersicon esculentum)
  • toxoplasmosis (Toxoplasma gondii)
  • Trichoplax (Trichoplax adhaerens)
  • wheat (Triticum aestivum)
  • worm (Caenorhabditis elegans)

Evolution for SPG21 Gene

Gene Tree for SPG21 (if available)
Gene Tree for SPG21 (if available)

Paralogs for SPG21 Gene

No data available for Paralogs for SPG21 Gene

Variants for SPG21 Gene

Sequence variations from dbSNP and Humsavar for SPG21 Gene

SNP ID Clin Chr 15 pos Sequence Context AA Info Type
rs7322 -- 64,963,363(-) GTGCA(A/G)ATTTT utr-variant-3-prime
rs4989150 -- 64,972,648(+) GAACA(C/T)GGTGA intron-variant
rs5813335 -- 64,985,359(+) TATCT(-/G)GTTGA intron-variant
rs5813336 -- 64,986,699(+) CAAAA(-/ACAAA/ACAAAA/CAAAA)AACAA intron-variant
rs6494505 -- 64,966,671(+) gaggc(A/G)ggcag intron-variant

Structural Variations from Database of Genomic Variants (DGV) for SPG21 Gene

Variant ID Type Subtype PubMed ID
nsv833041 CNV Loss 17160897
nsv510404 CNV Loss 20534489

Variation tolerance for SPG21 Gene

Residual Variation Intolerance Score: 18.7% of all genes are more intolerant (likely to be disease-causing)
Gene Damage Index Score: 0.64; 13.67% of all genes are more intolerant (likely to be disease-causing)

Relevant External Links for SPG21 Gene

Human Gene Mutation Database (HGMD)

No data available for Polymorphic Variants from UniProtKB/Swiss-Prot for SPG21 Gene

Disorders for SPG21 Gene

MalaCards: The human disease database

(9) MalaCards diseases for SPG21 Gene - From: OMIM, ClinVar, GeneTests, Orphanet, DISEASES, and GeneCards

Disorder Aliases PubMed IDs
mast syndrome
  • autosomal recessive spastic paraplegia 21
  • paraplegia, lower
  • firesetting behavior
  • pathological stealing
compartment syndrome
  • compartmental syndrome, nos
- elite association - COSMIC cancer census association via MalaCards
Search SPG21 in MalaCards View complete list of genes associated with diseases


  • Spastic paraplegia 21, autosomal recessive (SPG21) [MIM:248900]: A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body. SPG21 is associated with dementia and other central nervous system abnormalities. Subtle childhood abnormalities may be present, but the main features develop in early adulthood. The disease is slowly progressive, and cerebellar and extrapyramidal signs are also found in patients with advanced disease. Patients have a thin corpus callosum and white-matter abnormalities. {ECO:0000269 PubMed:14564668}. Note=The disease is caused by mutations affecting the gene represented in this entry.

Relevant External Links for SPG21

Atlas of Genetics and Cytogenetics in Oncology and Haematology:
genes like me logo Genes that share disorders with SPG21: view

No data available for Genatlas for SPG21 Gene

Publications for SPG21 Gene

  1. Cloning of ACP33 as a novel intracellular ligand of CD4. (PMID: 11113139) Zeitlmann L. … Kolanus W. (J. Biol. Chem. 2001) 2 3 4 23 67
  2. Maspardin is mutated in Mast syndrome, a complicated form of hereditary spastic paraplegia associated with dementia. (PMID: 14564668) Simpson M.A. … Crosby A.H. (Am. J. Hum. Genet. 2003) 2 3 23
  3. Interaction of the SPG21 protein ACP33/maspardin with the aldehyde dehydrogenase ALDH16A1. (PMID: 19184135) Hanna M.C. … Blackstone C. (Neurogenetics 2009) 3 23
  4. A proteome-scale map of the human interactome network. (PMID: 25416956) Rolland T. … Vidal M. (Cell 2014) 3
  5. Host-pathogen interactome mapping for HTLV-1 and -2 retroviruses. (PMID: 22458338) Simonis N. … Twizere J.C. (Retrovirology 2012) 3

Products for SPG21 Gene

Sources for SPG21 Gene