SNRNP35

SNRNP35 is a subunit of the human U11 snRNP, a building block of the minor spliceosome that mediates U12-type pre-mRNA splicing (PMID:39809272). Within the 13-subunit U11 snRNP, SNRNP35 directly contacts U11 snRNA, contributing to the structural organization of the particle that recognizes the incoming 5' splice site near the 5' end of U11 snRNA, where SNRNP48 and ZMAT5 stabilize substrate binding (PMID:39809272). Beyond this structural role in U11 snRNA recognition defined by cryo-EM, no further mechanistic detail has been characterized in the available corpus.

1. 2025 High

   Whether and how SNRNP35 engages the minor spliceosome was unresolved; cryo-EM of the human U11 snRNP placed SNRNP35 in direct contact with U11 snRNA, establishing it as an snRNA-recognition subunit of the minor-class splicing machinery.

   Evidence Cryo-EM reconstruction of the 13-subunit human U11 snRNP in apo and substrate-bound states

   PMID:39809272

   Open questions at the time

   • Functional consequence of SNRNP35 loss on minor-class splicing not tested
   • No biochemical dissection of SNRNP35's individual contribution to U11 snRNA binding versus the overall complex
   • No data on SNRNP35 outside the assembled U11 snRNP

• How SNRNP35 contributes functionally to 5' splice site recognition and minor-class splicing fidelity, and its behavior outside the structural complex, remain undefined.
• No perturbation/depletion studies linking SNRNP35 to splicing outcomes
• No identification of SNRNP35 domains required for U11 snRNA binding