Question

Chronic lymphocytic leukemia patients often harbor nonsense mutations in their spliceosome machinery. Describe how this mutation of the spliceosome would change the final location and sequence of a pre-mRNA.

a) It would result in the deletion of exons and intron retention.
b) It would cause intron excision but no changes in exon sequences.
c) It would alter the 3’ untranslated region of mRNA.
d) It would lead to alternative splicing patterns, changing the protein sequence.

Answer 1

Mutations in the spliceosome of chronic lymphocytic leukemia patients can lead to alternative splicing, affecting the sequence and function of proteins produced from pre-mRNA.

Step-by-step explanation:

Nonsense mutations in the spliceosome machinery of chronic lymphocytic leukemia patients can lead to defects in pre-mRNA splicing. Such mutations may alter the recognition sequences for splicing at the ends of introns and exons or affect the functioning of the spliceosome's proteins and RNAs. This can result in alternative splicing patterns, which may either create new, possibly functional, protein variants or lead to nonfunctional proteins that contribute to disease. Alternative splicing is crucial, as it must occur with extreme precision, and even a single nucleotide error can render a protein dysfunctional.

Chronic lymphocytic leukemia (CLL) patients with nonsense mutations in their spliceosome machinery would experience changes in the final location and sequence of a pre-mRNA. Specifically, this mutation would lead to alternative splicing patterns, changing the protein sequence. Alternative splicing occurs when different combinations of exons are included in the final mRNA molecule, resulting in the production of multiple protein isoforms from a single gene. In the case of CLL patients, the mutations in the spliceosome machinery would disrupt the normal splicing process, leading to the production of abnormal proteins.