5OBN

NMR solution structure of U11/U12 65K protein's C-terminal RRM domain (381-516)

Summary for 5OBN

• Entry DOI: 10.2210/pdb5obn/pdb
• NMR Information: BMRB: 34155
• Descriptor: RNA-binding protein 40 (1 entity in total)
• Functional Keywords: minor spliceosome, rna binding, splicing
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 1
• Total formula weight: 15796.29

Authors

Norppa, A.J.,Kauppala, T.M.,Heikkinen, H.A.,Verma, B.,Iwai, H.,Frilander, M.J. (deposition date: 2017-06-28, release date: 2018-01-24, Last modification date: 2024-06-19)

Primary citation

Norppa, A.J.,Kauppala, T.M.,Heikkinen, H.A.,Verma, B.,Iwai, H.,Frilander, M.J.
Mutations in the U11/U12-65K protein associated with isolated growth hormone deficiency lead to structural destabilization and impaired binding of U12 snRNA.
RNA, 24:396-409, 2018

PubMed Abstract: Mutations in the components of the minor spliceosome underlie several human diseases. A subset of patients with isolated growth hormone deficiency (IGHD) harbors mutations in the gene, which encodes the minor spliceosome-specific U11/U12-65K protein. Although a previous study showed that IGHD patient cells have defects in U12-type intron recognition, the biochemical effects of these mutations on the 65K protein have not been characterized. Here, we show that a proline-to-threonine missense mutation (P474T) and a nonsense mutation (R502X) in the C-terminal RNA recognition motif (C-RRM) of the 65K protein impair the binding of 65K to U12 and U6atac snRNAs. We further show that the nonsense allele is targeted to the nonsense-mediated decay (NMD) pathway, but in an isoform-specific manner, with the nuclear-retained long-3'UTR isoform escaping the NMD pathway. In contrast, the missense P474T mutation leads, in addition to the RNA-binding defect, to a partial defect in the folding of the C-RRM and reduced stability of the full-length protein, thus reducing the formation of U11/U12 di-snRNP complexes. We propose that both the C-RRM folding defect and NMD-mediated decrease in the levels of the U11/U12-65K protein reduce formation of the U12-type intron recognition complex and missplicing of a subset of minor introns leading to pituitary hypoplasia and a subsequent defect in growth hormone secretion.

PubMed: 29255062
DOI: 10.1261/rna.062844.117

Experimental method

SOLUTION NMR