Related Experiment Video

Updated: Aug 8, 2026

Engineering Artificial Factors to Specifically Manipulate Alternative Splicing in Human Cells
10:06

Engineering Artificial Factors to Specifically Manipulate Alternative Splicing in Human Cells

Published on: April 26, 2017

Biochemical characterization of apoptotic cleavage of KH-type splicing regulatory protein (KSRP)/far upstream

Heeyoung Seok1, Jinsun Cho, Minseok Cheon

  • 1Research Center for Proteineous Materials and Department of Bio-Materials Engineering, Chosun University, 375 Seosuk-Dong, Dong-Ku, Gwangju 501-759, Republic of Korea.

Protein and Peptide Letters
|January 30, 2003
PubMed

Insights

Researchers identified KSRP/FBP2 as a new nuclear caspase substrate. Caspase-3 and -7 cleave KSRP/FBP2 at two sites, suggesting protein structure, not just sequence, influences caspase recognition during apoptosis.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Background:

  • Caspases are aspartate-specific cysteine proteases crucial for initiating apoptosis.
  • Identifying caspase substrates is vital for understanding apoptotic pathways.
  • Nuclear protein processing during apoptosis remains an area of active research.

Purpose of the Study:

  • To identify and characterize novel nuclear caspase substrates.
  • To investigate the cleavage sites and specificity of caspases on identified substrates.

Main Methods:

  • Proteomic analysis of rat liver extracts treated with caspases.
  • Identification of protein cleavage products using mass spectrometry.
  • Site-directed mutagenesis and in vitro translation to analyze cleavage site recognition.

Main Results:

  • KSRP/FBP2 (hnRNP K-like splicing regulatory protein/FBP2) was identified as a novel nuclear caspase substrate.
  • KSRP/FBP2 is preferentially cleaved by caspase-3 and caspase-7 at Asp102 and Asp183.
  • Cleavage at Asp183 occurred only in cellular proteins, not in vitro translated proteins, indicating post-translational modifications or protein folding influence recognition.

Conclusions:

  • KSRP/FBP2 is a novel nuclear substrate for executioner caspases (caspase-3 and -7).
  • Caspase-mediated cleavage of KSRP/FBP2 occurs at specific aspartate residues.
  • The cellular context, including protein folding and potential post-translational modifications, plays a significant role in caspase substrate recognition beyond primary amino acid sequence.

More Related Videos

Exploring Sequence Space to Identify Binding Sites for Regulatory RNA-Binding Proteins11:34

Exploring Sequence Space to Identify Binding Sites for Regulatory RNA-Binding Proteins

Published on: August 9, 2019

Using the E1A Minigene Tool to Study mRNA Splicing Changes10:25

Using the E1A Minigene Tool to Study mRNA Splicing Changes

Published on: April 22, 2021

Related Concept Videos

RNA Splicing01:32

RNA Splicing

Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
Chromatin Structure Regulates pre-mRNA Processing02:41

Chromatin Structure Regulates pre-mRNA Processing

In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
Alternative RNA Splicing02:18

Alternative RNA Splicing

Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
The Extrinsic Apoptotic Pathway01:17

The Extrinsic Apoptotic Pathway

The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...