sum more nerve wrecking NBme!!!! - poojy36

[ArchivalUser]

1)a prot containing 30 aa structural motiff with 4 cysteine residues coordinated with zn atom .in which of teh foll is this structure most likely present ?

a)nucleosome b)ribonuclease c)ribosome d)splicosome
e)transcription factors

2) which immuno supressive agents acts in the lymphocyte by complexing to and inactivating lymphocyte specific phosphatase calcineurin?

a)lymphocyte globulin
b)azathioprim
c0corticosteroids
d)cyclosporine
e)OKT3 monoclonal antibody

PS: DOES ANYONE HAVE SUM GOOD EXPLANATION FOR THE MECH OF ACTIONS OF IMMUNOSUPRESSANTS.??

[ArchivalUser]

1. they are talking about zinc finger, it is a transcription factor

2. cyclosporine.

[ArchivalUser]

Signaling via T-cell receptor-associated tyrosine kinases leads to the activation and increased synthesis of the transcription factor AP-1 and other partner proteins, as well as increasing the concentration of Ca2+ in the cytoplasm. The Ca2+ binds to calcineurin and thereby activates it to dephosphorylate the cytoplasmic form of members of the family of nuclear factors of activated T cells (NFATc). Once dephosphorylated, the active NFATc family members migrate to the nucleus to form a complex with AP-1 and other partner proteins; the NFATc:AP-1 complexes can then induce the transcription of genes required for T-cell activation, including the IL-2 gene. When cyclosporin A (CsA) or tacrolimus are present, they form complexes with their immunophilin targets, cyclophilin (CyP) and FK-binding protein (FKBP), respectively. The complex of cyclophilin with cyclosporin A can bind to calcineurin and block its ability to activate NFATc family members. The complex of tacrolimus with FKBP binds to calcineurin at the same site, also blocking its activity.