STAR (Steroidogenic Acute Regulatory Protein) Gene

Key regulator of steroid hormone biosynthesis, cholesterol transport in mitochondria

Gene Information Card

Symbol STAR
Full Name Steroidogenic Acute Regulatory Protein
Gene Type Protein coding
Chromosomal Location 8p11.23
NCBI Gene ID 6770 ncbi.nlm.nih.gov/gene/6770
Ensembl ID ENSG00000147454
UniProt ID P49675
OMIM ID 600617
HGNC ID 11359
Aliases StAR, STARD1, LCAH, lipoid congenital adrenal hyperplasia

Description

The STAR gene encodes the steroidogenic acute regulatory protein (StAR), which mediates the rate-limiting step in steroidogenesis: the transfer of cholesterol from the outer to the inner mitochondrial membrane. This protein is essential for the synthesis of all steroid hormones in the adrenal glands, gonads, and placenta. Mutations in STAR cause lipoid congenital adrenal hyperplasia (LCAH), a severe disorder of steroid hormone deficiency.

Disease Associations

Disease category Pathophysiological mechanism Genomic evidence
Lipoid Congenital Adrenal Hyperplasia (LCAH) Loss-of-function mutations impair cholesterol transport into mitochondria, blocking steroidogenesis and causing adrenal insufficiency with lipid accumulation. OMIM #201710, ClinVar, multiple case reports
Primary Adrenal Insufficiency Deficient StAR activity leads to cortisol and aldosterone deficiency, often presenting in infancy. ClinVar, NCBI GeneReviews
46,XY Sex Reversal In males, impaired testosterone synthesis due to StAR deficiency causes undervirilization or female external genitalia. OMIM, literature

Expression Profile

Tissue Expression
Tissue nTPM level
Adrenal gland High Tissue-specific high expression
Ovary High Theca interna, corpus luteum
Testis High Leydig cells
Placenta Moderate Syncytiotrophoblast
Kidney Low Minimal expression
Brain Low Some regions
Cell Line Expression
Cell Line nTPM Notes
NCI-H295R (adrenocortical) High Steroidogenic cell line
KGN (ovarian granulosa) Moderate Steroidogenic
HeLa Low Non-steroidogenic
HEK293 Low Non-steroidogenic
Data source：Human Protein Atlas（proteinatlas.org）

Mutations & Variants

Hotspot Mutations
Variant Type Frequency Functional Description
c.772C>T (p.Arg258Trp) Missense Common in Japanese LCAH Loss of function, impaired cholesterol binding
c.201_202delCT (p.Phe68Leufs*5) Frameshift Reported in multiple ethnicities Complete loss of StAR activity
c.653C>A (p.Ala218Asp) Missense Rare Reduced mitochondrial import
c.560G>A (p.Arg187His) Missense Found in compound heterozygotes Partial loss of function
Mutation functional classification

Loss of Function (LOF)

Most STAR mutations cause complete or partial loss of cholesterol transport activity, leading to LCAH.

Gain of Function (GOF)

Not reported; gain-of-function mutations are not associated with any known phenotype.

Dominant Negative (DN)

No dominant-negative STAR mutations described; disease is autosomal recessive.
View complete mutation data：
ClinVar：https://www.clinvar.com/gene/6770
COSMIC：https://cancer.sanger.ac.uk/cosmic/gene/analysis?ln=STAR

Gene Ontology (GO)

• transporter activity (GO:0005215) • lipid transporter activity (GO:0005319)
• cholesterol binding (GO:0015485) • steroid biosynthetic process (GO:0006694)
• mitochondrial outer membrane (GO:0005741) • mitochondrial inner membrane (GO:0005743)
• mitochondrial membrane (GO:0031966)

Pathways

• Steroid hormone biosynthesis (KEGG: hsa00140)
• Metabolism of steroids (Reactome: R-HSA-196108)
• Cholesterol import into mitochondria (Reactome: R-HSA-196071)

Protein Summary

StAR is a 285-amino acid protein with a mitochondrial targeting sequence and a C-terminal START domain that binds cholesterol. It is synthesized as a 37 kDa precursor, imported into mitochondria, and cleaved to a 30 kDa mature form. The protein facilitates cholesterol transfer to the inner mitochondrial membrane where CYP11A1 (P450scc) initiates steroidogenesis. StAR activity is acutely regulated by cAMP/PKA signaling.

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Related Products

Product name Cat.No. Species Gene ID
STARD3 Knockout HEK293 Cell Line EDJ-KQ3348 Human 10948 Details Get a Quote
STARD13 Knockout HEK293 Cell Line EDJ-KQ3917 Human 90627 Details Get a Quote
STAR Knockout HEK293 Cell Line EDJ-KQ5856 Human 6770 Details Get a Quote
STARD8 Knockout HEK293 Cell Line EDJ-KQ6732 Human 9754 Details Get a Quote
STARD10 Knockout HEK293 Cell Line EDJ-KQ7184 Human 10809 Details Get a Quote
STARD4 Knockout HEK293 Cell Line EDJ-KQ9340 Human 134429 Details Get a Quote
STARD6 Knockout HEK293 Cell Line EDJ-KQ9874 Human 147323 Details Get a Quote
STARD3NL Knockout HEK293 Cell Line EDJ-KQ9936 Human 83930 Details Get a Quote
STARD7 Knockout HEK293 Cell Line EDJ-KQ15533 Human 56910 Details Get a Quote
STARD9 Knockout HEK293 Cell Line EDJ-KQ15534 Human 57519 Details Get a Quote
STARD3 Knockout A-549 Cell Line EDJ-KQ24997 Human 10948 Details Get a Quote
STARD3 Knockout HCT 116 Cell Line EDJ-KQ24998 Human 10948 Details Get a Quote
STARD3 Knockout HeLa Cell Line EDC09857 Human 10948 Details Get a Quote
STARD13 Knockout A-549 Cell Line EDJ-KQ26141 Human 90627 Details Get a Quote
STARD13 Knockout HCT 116 Cell Line EDJ-KQ26142 Human 90627 Details Get a Quote
Displaying Records 1 To 15 Of 44 Records

Reference Databases

NCBI Gene https://www.ncbi.nlm.nih.gov/gene/6770
OMIM https://www.omim.org/entry/600617
HGNC https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:11359
Ensembl https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000147454
UniProt https://www.uniprot.org/uniprot/P49675
ClinVar https://www.ncbi.nlm.nih.gov/clinvar/?term=STAR%5Bgene%5D
COSMIC https://cancer.sanger.ac.uk/cosmic/gene/analysis?ln=STAR
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