Related Experiment Video

Updated: Aug 21, 2026

Measuring Enzymatic Activity of Neurodevelopmental Disorder-Associated Deubiquitylating Enzymes via an In Vitro Ubiquitin Chain Cleavage Assay
07:05

Measuring Enzymatic Activity of Neurodevelopmental Disorder-Associated Deubiquitylating Enzymes via an In Vitro Ubiquitin Chain Cleavage Assay

Published on: September 27, 2024

Two closely related ubiquitin C-terminal hydrolase isozymes function as reciprocal modulators of germ cell apoptosis

Jungkee Kwon1, Yu-Lai Wang, Rieko Setsuie

  • 1Department of Degenerative Neurological Disease, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, 187-8502, Japan.

The American Journal of Pathology
|October 7, 2004
PubMed

Insights

Ubiquitin C-terminal hydrolase L1 (UCH-L1) protects against testicular injury, while UCH-L3 promotes germ cell apoptosis. These enzymes differentially regulate cell survival proteins, impacting male fertility during cryptorchid stress.

Area of Science:

  • Molecular Biology
  • Reproductive Biology
  • Cellular Biology

Background:

  • The ubiquitin-proteasome system regulates cellular protein degradation and is implicated in apoptosis.
  • Testicular germ cell apoptosis is a critical process in male reproductive health.
  • Cryptorchidism serves as a model to study in vivo germ cell apoptosis.

Purpose of the Study:

  • To investigate the distinct roles of UCH-L1 and UCH-L3 in cryptorchidism-induced testicular germ cell apoptosis.
  • To elucidate the molecular mechanisms by which UCH-L1 and UCH-L3 influence apoptotic and survival protein levels.

Main Methods:

  • Utilized cryptorchid mouse models, including gracile axonal dystrophy (gad) mice lacking UCH-L1 and Uchl3 knockout mice.
  • Analyzed testicular tissue for ubiquitin levels, protein expression (anti-apoptotic, prosurvival, and apoptotic markers), and histological changes.
  • Compared responses to cryptorchid stress between wild-type and knockout mice.

Main Results:

  • Mice lacking UCH-L1 (gad mice) showed resistance to cryptorchid stress, with reduced ubiquitin and elevated anti-apoptotic/prosurvival proteins.
  • Uchl3 knockout mice exhibited severe testicular atrophy and germ cell loss following cryptorchid injury.
  • UCH-L1 deficiency preserved survival proteins, whereas UCH-L3 deficiency increased apoptotic markers like p53, Bax, and caspase3.

Conclusions:

  • UCH-L1 and UCH-L3 exhibit opposing and differential functions in regulating testicular germ cell apoptosis.
  • UCH-L1 acts as a protective factor against testicular stress by maintaining survival pathways.
  • UCH-L3 appears to promote germ cell apoptosis, influencing the balance of cell death and survival proteins.

More Related Videos

A Seminiferous Tubule Squash Technique for the Cytological Analysis of Spermatogenesis Using the Mouse Model09:40

A Seminiferous Tubule Squash Technique for the Cytological Analysis of Spermatogenesis Using the Mouse Model

Published on: February 6, 2018

In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones11:36

In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones

Published on: July 25, 2019

Related Concept Videos

Protein Complexes with Interchangeable Parts01:57

Protein Complexes with Interchangeable Parts

Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
Caspases01:24

Caspases

Caspase, a family of cysteine proteases, serve as effectors in apoptosis. The ced3 gene in C.elegans was first identified to be involved in apoptosis. This gene encodes the ced-3 caspase that is similar to the interleukin-1-beta converting enzyme or ICE in mammals. In addition to apoptosis, caspases also function in the inflammatory response. Inflammatory caspases are essential in activating pro-inflammatory cytokines that recruit immune cells and block the replication of pathogens inside cells.
Anaphase Promoting Complex00:50

Anaphase Promoting Complex

The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
Regulated Protein Degradation02:58

Regulated Protein Degradation

It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR activation may...
The Proteasome01:13

The Proteasome

Eukaryotic cells can degrade proteins through several pathways. One of the most important among these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...