We have used a site-specific cross-linking strategy to identify RNA and protein factors that interact with the 5' splice site region during mammalian pre-mRNA splicing. Two different pre-mRNA substrates were synthesized with a single 32P-labeled 4-thiouridine residue 2 nucleotides upstream of the 5' splice site. Selective photoactivation of the 4-thiouridine residue after incubation of either substrate under splicing conditions in HeLa nuclear extract resulted in cross-links to the U5 snRNA and the U5 snRNP protein p220. These ATP-dependent interactions occur before the first step of splicing. The U5 snRNA cross-links map to a phylogenetically invariant 9-nucleotide loop sequence and do not require Watson-Crick complementarity to the 5' exon. Cross-links of this position in the pre-mRNA to U1, but not to U2, U4, or U6 snRNAs, were also observed. The kinetics of U1 and U5 cross-link formation are similar, both peaking well before reaction intermediates appear.
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http://dx.doi.org/10.1101/gad.6.12b.2542 | DOI Listing |
Indian J Med Res
November 2024
Department of Clinical Genetics, Christian Medical College, Vellore, Tamil Nadu, India.
Background & objectives Alkaptonuria (AKU) is an autosomal recessive disease wherein biallelic pathogenic variants in the homogentisate 1,2- dioxygenase (HGD) gene encoding the enzyme homogentisate 1,2 dioxygenase cause high levels of homogentisic acid (HGA) to circulate within the body leading to its deposition in connective tissues and excretion in urine. A homozygous splice donor variant (c.87+1G>A) has been identified to be the founder variant causing alkaptonuria among Narikuravars, a group of gypsies settled in Tamil Nadu.
View Article and Find Full Text PDFMol Cancer
December 2024
Department of Hepatobiliary Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
Background: Posttranslational modifications (PTMs) play critical roles in hepatocellular carcinoma (HCC). However, the locations of PTM-modified sites across protein secondary structures and regulatory patterns in HCC remain largely uncharacterized.
Methods: Total proteome and nine PTMs (phosphorylation, acetylation, crotonylation, ubiquitination, lactylation, N-glycosylation, succinylation, malonylation, and β-hydroxybutyrylation) in tumor sections and paired normal adjacent tissues derived from 18 HCC patients were systematically profiled by 4D-Label free proteomics analysis combined with PTM-based peptide enrichment.
J Transl Med
December 2024
Department of Breast Surgery, College of Medicine, The First Affiliated Hospital, Zhejiang University, Hangzhou, 310000, Zhejiang, China.
Background: Aberrant alternative splicing (AS) contributes to tumor progression. A crucial component of AS is cleavage and polyadenylation specificity factor 4 (CPSF4). It remains unclear whether CPSF4 plays a role in triple-negative breast cancer (TNBC) progression through AS regulation.
View Article and Find Full Text PDFBMC Pediatr
December 2024
Department of Endocrinology and Metabolism, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 1678 Dongfang Road, Shanghai, 200127, China.
The ARCN1 gene encodes the delta subunit of the coatomer protein complex I (COPI), which is essential for mediating protein transport from the Golgi complex to the endoplasmic reticulum. Variants in ARCN1 are associated with clinical features such as microcephaly, microretrognathia, intrauterine growth restriction, short rhizomelic stature, and developmental delays. We present a case of a patient exhibiting intrauterine growth restriction, preterm birth, microcephaly, micrognathia, and central precocious puberty.
View Article and Find Full Text PDFCurr Biol
December 2024
The Hormel Institute, University of Minnesota, Austin, MN 55912, USA; Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA. Electronic address:
Serine 31 is a phospho-site unique to the histone H3.3 variant; mitotic phospho-Ser31 is restricted to pericentromeric heterochromatin, and disruption of phospho-Ser31 results in chromosome segregation defects and loss of p53-dependant G cell-cycle arrest. Ser31 is proximal to the H3.
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