Replacement of Alanine with Asparagic Acid at Position 203 in Human Steroidogenic Acute Regulatory Protein Impairs the Ability to Enhance Steroidogenesis in vitro

Abstract Hormone-induced steroid biosynthesis begins with the transfer of cholesterol from intracellular stores into mitochondria. Steroidogenic acute regulatory protein (StAR) and peripheral-type benzodiazepine receptor (PBR) have been implicated in this rate-determining step of steroidogenesis. MA-10 mouse Leydig tumor cells were treated with and without oligodeoxynucleotides (ODNs) antisense to PBR and StAR followed by treatment with saturating concentrations of human choriogonadotropin. Treatment with ODNs antisense but not missense for both proteins inhibited the respective protein expression and the ability of the cells to synthesize steroids in response to human choriogonadotropin. Treatment of the cells with either ODNs antisense to PBR or a transducible peptide antagonist to PBR resulted in inhibition of the accumulation of the mature mitochondrial 30-kDa StAR protein, suggesting that the presence of PBR is required for StAR import into mitochondria. Addition of in vitro transcribed/translated 37-kDa StAR or a fusion protein of Tom20 (translocase of outer membrane) and StAR (Tom/StAR) to mitochondria isolated from control cells increased pregnenolone formation. Mitochondria isolated from cells treated with ODNs antisense, but not missense, to PBR failed to form pregnenolone and respond to either StAR or Tom/StAR proteins. Reincorporation of in vitro transcribed/translated PBR, but not PBR missing the cholesterol-binding domain, into MA-10 mitochondria rescued the ability of the mitochondria to form steroids and the ability of the mitochondria to respond to StAR and Tom/StAR proteins. These data suggest that both StAR and PBR proteins are indispensable elements of the steroidogenic machinery and function in a coordinated manner to transfer cholesterol into mitochondria.

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Differences in steroidogenic acute regulatory protein expression from the luteinizing-granulosa cells of patients undergoing in vitro fertilization with embryo transfer: Implications for cycle outcomes

American Journal of Obstetrics and Gynecology ◽

10.1067/mob.2002.123410 ◽

2002 ◽

Vol 186 (5) ◽

pp. 872-875 ◽

Cited By ~ 5

Author(s):

Jennifer Phy ◽

Douglas M. Stocco ◽

Samuel D. Prien

Keyword(s):

In Vitro Fertilization ◽

Protein Expression ◽

Embryo Transfer ◽

Granulosa Cells ◽

Regulatory Protein ◽

Steroidogenic Acute Regulatory Protein ◽

Vitro Fertilization ◽

Steroidogenic Acute Regulatory

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Effects of ACTH and cAMP on steroidogenic acute regulatory protein and P450 11β-hydroxylase messenger RNAs in rainbow trout interrenal cells: Relationship with in vitro cortisol production

General and Comparative Endocrinology ◽

10.1016/j.ygcen.2005.09.014 ◽

2006 ◽

Vol 145 (3) ◽

pp. 254-262 ◽

Cited By ~ 46

Author(s):

I. Julie Hagen ◽

Makoto Kusakabe ◽

Graham Young

Keyword(s):

Rainbow Trout ◽

Regulatory Protein ◽

Steroidogenic Acute Regulatory Protein ◽

Messenger Rnas ◽

Interrenal Cells ◽

Steroidogenic Acute Regulatory

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Steroidogenic acute regulatory protein and luteinizing hormone are required for normal ovarian steroidogenesis and oocyte maturation in zebrafish†

Biology of Reproduction ◽

10.1093/biolre/ioz132 ◽

2019 ◽

Vol 101 (4) ◽

pp. 760-770 ◽

Cited By ~ 4

Author(s):

Guohui Shang ◽

Xuyan Peng ◽

Cheng Ji ◽

Gang Zhai ◽

Yonglin Ruan ◽

...

Keyword(s):

Luteinizing Hormone ◽

Oocyte Maturation ◽

Mitochondrial Membrane ◽

Regulatory Protein ◽

Steroidogenic Acute Regulatory Protein ◽

Transcription Activator ◽

Inner Mitochondrial Membrane ◽

Steroidogenic Acute Regulatory ◽

Functional Deficiency

Abstract In recent studies, luteinizing hormone (LH) was reported to play important roles in oocyte maturation. However, the mechanism by which LH signaling, especially regarding the steroidogenesis process, affects oocyte maturation has not been clarified. In this study, zebrafish models with a functional deficiency in luteinizing hormone beta (Lhb) or steroidogenic acute regulatory protein (Star), an enzyme that promotes the transport of cholesterol into the inner mitochondrial membrane for maturation-induced hormone (MIH) production, were generated using transcription activator-like effector nucleases (TALENs). Similar phenotypes of the maturation-arrested oocytes in both female mutants have been observed. The levels of MIH in the oocytes of the female mutants were clearly decreased in both the lhb and star knockout zebrafish. The expression of star was dramatically down-regulated in the lhb mutant follicles and was clearly promoted by forskolin and hCG in vitro. Furthermore, treatment with the MIH precursors, pregnenolone or progesterone, as well as with MIH itself rescued the maturation-arrested oocyte phenotypes in both lhb and star mutants. The plasma levels of other steroids, including testosterone, estradiol, and cortisol, were not affected in the lhb mutants, while the levels of gonad hormones testosterone and estradiol were significantly increased in the star mutants. The cortisol levels were decreased in the star mutants. Collectively, our results confirm that LH plays important roles in the initiation of MIH synthesis from cholesterol and maintains oocyte maturation in zebrafish, as well as provide evidence that Star might act downstream of LH signaling in steroidogenesis.

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Steroid production after in vitro transcription, translation, and mitochondrial processing of protein products of complementary deoxyribonucleic acid for steroidogenic acute regulatory protein.

Endocrinology ◽

10.1210/endo.136.11.7588255 ◽

1995 ◽

Vol 136 (11) ◽

pp. 5165-5176 ◽

Cited By ~ 51

Author(s):

S R King ◽

T Ronen-Fuhrmann ◽

R Timberg ◽

B J Clark ◽

J Orly ◽

...

Keyword(s):

Deoxyribonucleic Acid ◽

Regulatory Protein ◽

In Vitro Transcription ◽

Steroidogenic Acute Regulatory Protein ◽

Steroid Production ◽

Complementary Deoxyribonucleic Acid ◽

Steroidogenic Acute Regulatory

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The Contribution of Serine 194 Phosphorylation to Steroidogenic Acute Regulatory Protein Function

Molecular Endocrinology ◽

10.1210/me.2014-1028 ◽

2014 ◽

Vol 28 (7) ◽

pp. 1088-1096 ◽

Cited By ~ 18

Author(s):

Goro Sasaki ◽

Mohamad Zubair ◽

Tomohiro Ishii ◽

Toshikatsu Mitsui ◽

Tomonobu Hasegawa ◽

...

Keyword(s):

Adrenal Cortex ◽

Protein Function ◽

Regulatory Protein ◽

Initial Step ◽

Artificial Chromosome ◽

Steroidogenic Acute Regulatory Protein ◽

Inner Mitochondrial Membrane ◽

Steroidogenic Acute Regulatory

The steroidogenic acute regulatory protein (StAR) facilitates the delivery of cholesterol to the inner mitochondrial membrane, where the cholesterol side-chain cleavage enzyme catalyzes the initial step of steroid hormone biosynthesis. StAR was initially identified in adrenocortical cells as a phosphoprotein, the expression and phosphorylation of which were stimulated by corticotropin. A number of in vitro studies have implicated cAMP-dependent phosphorylation at serine 194 (S194, S195 in human StAR) as an important residue for StAR activity. To explore the importance of S194 phosphorylation in StAR function in vivo, we developed a transgenic model using a bacterial artificial chromosome expressing either wild-type (WT) StAR or StAR mutation S194A to rescue StAR knockout (KO) mice. Despite StAR protein expression comparable to or higher than amounts seen with control animals or rescue with WT StAR, S194A StAR did not rescue the neonatal lethality and only partially rescued the sex reversal in male mice observed uniformly in StAR KO mice. Like the StAR KO mice, the adrenal cortex and testicular Leydig cells contained abundant lipid deposits when stained with oil red O. Adrenal StAR from S194A rescue animals lacks an acidic species, which appears upon corticotropin stimulation in animals rescued with WT StAR, consistent with defective StAR phosphorylation. These findings demonstrate that S194 is an essential residue for normal StAR function in the adrenal cortex and testes of mice.

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Von Hermaphroditos der griechischen Mythologie bis zu DSD der Moderne

Praxis ◽

10.1024/1661-8157.98.1.31 ◽

2008 ◽

Vol 98 (1) ◽

pp. 31-34

Author(s):

Oestmann ◽

Mullis ◽

Stanga

Keyword(s):

Regulatory Protein ◽

Steroidogenic Acute Regulatory Protein ◽

Sich Eine ◽

Fand Sich ◽

Steroidogenic Acute Regulatory

Wir berichten über eine heute 34-jährige Frau, die im Alter von 6 Monaten wegen rezidivierendem Erbrechen hospitalisiert werden musste. Als Ursache fand sich eine Nebenniereninsuffizienz mit Verminderung sämtlicher Hormone der Steroidhormonbiosynthese. Die weiteren Abklärungen ergaben bei dem phänotypisch weiblichen Säugling eine lipoide kongenitale adrenale Hyperplasie mit 46,XY DSD. 24 Jahre später konnte in der DNS-Sequenzanalyse ein homozygoter, in der Schweiz vorkommender Basenaustausch des steroidogenic acute regulatory protein-Gens gefunden werden, welcher zu einem Aminosäurenaustausch Leucin 260 Prolin (L260P) führt.

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