Identification of activated cryptic 5' splice sites using structure profiles and odds measure

OUP accepted manuscript

Alternative splicing (AS) and transcription elongation are vital biological processes, and their dysregulation causes multiple diseases, including tumors. However, the coregulatory mechanism of AS and transcription elongation in tumors remains unclear. This study demonstrates a novel AS pattern of tight junction protein 1 (ZO1) regulated by the RNA polymerase II elongation rate in colorectal cancer (CRC). Glioma tumor suppressor candidate region gene 1 (GLTSCR1) decreases the transcription elongation rate of ZO1 to provide a time window for binding of the splicing factor HuR to the specific motif in intron 22 of ZO1 and spliceosome recognition of the weak 3′ and 5′ splice sites in exon 23 to promote exon 23 inclusion. Since exon 23 inclusion in ZO1 suppresses migration and invasion of CRC cells, our findings suggest a novel potential therapeutic target for CRC.

A novel intronic homozygous mutation in the AMT gene of a patient with nonketotic hyperglycinemia and hyperammonemia

Nonketotic Hyperglycinemia is an autosomal recessive disorder characterized by defects in the mitochondrial glycine cleavage system. Most patients present soon after birth with seizures and hypotonia, and infants that survive the newborn period often have profound intellectual disability and intractable seizures. Here we present a case report of a 4-year-old girl with NKH as well as hyperammonemia, an uncommon finding in NKH. Genetic analysis found a previously unreported homozygous mutation (c.878-1 G > A) in the AMT gene. Maximum Entropy Principle modeling predicted that this mutation most likely breaks the splice site at the border of intron 7 and exon 8 of the AMT gene. Treatment with L-Arginine significantly reduced both the proband's glycine and ammonia levels, in turn aiding in control of seizures and mental status. This is the first time the use of L-Arginine is reported to successfully treat elevated glycine levels.