Functional probing of the human glucocorticoid receptor steroid-interacting surface by site-directed mutagenesis - Gln-642 plays an important role in steroid recognition and binding

To elucidate which amino acids in the glucocorticoid receptor ligand-binding domain might be involved in determining steroid binding specificity by interaction with the D-ring of glucocorticoids, we have performed site-directed mutagenesis of the four amino acids Met-560, Met-639, Gln-642, and Thr-739 based on their proximity to the steroid in a model structure. Mutations of these residues affected steroid binding affinity, specificity, and/or steroid-dependent transactivation. The results indicate that these residues are located in close proximity to the ligand and appear to play a role in steroid recognition and/or transactivating sensitivity, possibly by changes in the steroid-dependent conformational change of this region, resulting in the formation of the AF-2 site. Mutation of Gln-642 resulted in a marked decrease in affinity for steroids containing a 17 alpha-OH group. This effect was alleviated by the presence of a 16 alpha-CH3 group to a varying degree. Thr-739 appears to form a hydrogen bond with the 21-OH group of the steroid, as well as possibly forming hydrophobic interactions with the steroid, Met-EGO and Met-639 appear to form hydrophobic interactions with the D-ring of the steroid, although the nature of these interactions cannot be characterized in more detail at this point.

Greenidge, P (författare)
Gillner, M (författare)
Koehler, K F (författare)
Wright, Anthony P HKarolinska Institutet,Södertörns högskola,Avdelning Naturvetenskap,Karolinska Institute(Swepub:sh)SHAYWT (författare)
Carlstedt-Duke, JKarolinska Institutet (författare)
Södertörns högskolaAvdelning Naturvetenskap (creator_code:org_t)

Av författaren/redakt...: Lind, U; Greenidge, P; Gillner, M; Koehler, K F; Wright, Anthony ...; Carlstedt-Duke, ...

Om ämnet

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.