What does LARP1 prevent?
Biochemical analyses reveal that LARP1 selectively prevents the binding of eIF4E to the m7Gppp cap to block the assembly of the eIF4F complex on TOP mRNAs.
What does LARP1 stand for?
La-related protein 1
La-related protein 1 (LARP1) is a 150 kDa protein that in humans is encoded by the LARP1 gene.
What is top mRNA?
TOP mRNAs are vertebrate transcripts which contain a 5’terminal oligopyrimidine tract (5’TOP), encode for ribosomal proteins and elongation factors 1alpha and 2, and are candidates for growth-dependent translational control mediated through their 5’TOP.
What does cap binding protein do?
Molecular Basis of Memory eIF4E, the cap-binding protein promotes protein synthesis by binding to eIF4G. Beside its role in translation regulation, eIF4E is also important for mRNA stability and the proper subcellular localization of mRNA.
What is the function of LARP1 and where does it bind?
We show that LARP1 directly binds the cap and adjacent 5’TOP motif of TOP mRNAs, effectively impeding access of eIF4E to the cap and preventing eIF4F assembly. Thus, LARP1 is a specialized TOP mRNA cap-binding protein that controls ribosome biogenesis.
What is an Oligopyrimidine?
oligopyrimidine (countable and uncountable, plural oligopyrimidines) A portion of DNA or RNA containing several consecutive pyrimidine bases quotations ▼
Is Cap necessary for transcription?
The 5′ mRNA cap structure is essential for efficient gene expression from yeast to human. The cap structure protects mRNAs from degradation by exonucleases and promotes transcription, polyadenylation, splicing, and nuclear export of mRNA and U-rich, capped snRNAs.
What is a CAP-binding site?
In these operons, a CAP-binding site is located upstream of the RNA-polymerase-binding site in the promoter. This increases the binding ability of RNA polymerase to the promoter region and the transcription of the genes.
What is LARP in biology?
Four families of La-related proteins (LARPs) emerged during eukaryotic evolution with specialized functions. We provide an overview of the high-resolution structural biology of La and LARPs. LARP7 family members most closely resemble La but function with a single RNAP III nuclear transcript, 7SK, or telomerase RNA.
Which of the following codons is recognized by tRNA as the start site for translation?
Then a transfer RNA (tRNA) molecule carrying the amino acid methionine binds to what is called the start codon of the mRNA sequence. The start codon in all mRNA molecules has the sequence AUG and codes for methionine. Next, the large ribosomal subunit binds to form the complete initiation complex.
Why is poly-A tail important?
The polyA tail makes the RNA molecule more stable and prevents its degradation and allows the mature mRNA molecule to be exported from the nucleus and translated into a protein by ribosomes in the cytoplasm.