Dexamethasone

We purchase our Dexamethasone from Sigma, catalogue number D4902.

"Dexamethasone solutions are stable for at least 30 days when stored at 4°C and protected from light. The solution may be aliquoted and stored at -20°C." (Sigma).

We make a 2 mg/ml (~5x10-3 M) stock in 100% ethanol and store it at -20°C. This is a 500x stock, with the final working concentration 1x10-5 M.

In our hands the water soluble Dex (Sigma D2915) does not work when applied to Xenopus embryos.

Other Steroid Hormones

(Adapted from Mattioni et al., 1994)

Receptora

amino acid positionsb

ligand 

concentrationc

references 

GR

~512-~777 (human)

dexamethasone

10 uM (X)

(Mattioni et al., 1994; Kolm and Sive, 1995)

ER

282-595 (human)

17b-estradiol

10 nM(tc)-1uM(X)

(Mattioni et al., 1994; Kolm and Sive, 1995)

ER*

282-595 (human)

4-hydroxy tamoxifen

200 nM

(Littlewood et al., 1995)

PR

~670-933 (human)

progesterone

100 nM - 1uM

(Mattioni et al., 1994)

PR*

671-891 (human)

RU486

1-100 nM

(Kellendonk et al., 1996)

MR

685-981 (rat)

aldosterone

10 nM

(Mattioni et al., 1994)

AR

~650-918 (human)

5a-dihydrotestosterone

100 nM

(Mattioni et al., 1994)

TRa

164-410 (rat)

triiodothyronine

100 nM (tc, X)

(Hollenberg et al., 1993; Kolm, unpublished)

EcRd

329-878 (Drosophila)

muristerone A

100 nM - 10 uM

(Christopherson et al., 1992; No et al., 1996)

RARa

176-462 (human)

retinoic acid

0.1-10 uM

(Takebayashi et al., 1996)

         

a.AR: androgen receptor; ER: estrogen receptor; ER*: mutated estrogen receptor; EcR: ecdysone receptor; GR: glucocorticoid receptor; MR: mineralocorticoid receptor; PR: progesterone receptor; PR*: mutated progesterone receptor; RAR: retinoic acid receptor; TR: thyroid hormone receptor

b. Listed are the approximate amino acid positions for the ligand binding domain from the species noted. Since these proteins are highly conserved, the corresponding hbd sequences from other species can also be used.

c. Concentrations listed are optimal for tissue culture cells, unless otherwise noted. X: Used in Xenopus; tc: used in tissue culture

d. May require co-expression of a heterodimeric partner such as RXR or USP (No et al., 1996; Takebayashi et al., 1996).