Vasanta Subramanian and colleagues from the University of Bath identified the protein as angiogenin, which is needed for the growth of blood vessels. But they discovered mutant forms of the protein are toxic to the motor neurons that initiate and control muscle contractions.
The researchers believe the gradual accumulation of the mutant proteins might explain the late onset and gradual deterioration of function caused by ALS, eventually leading to death. Subramanian said targeting the altered form of angiogenin might make it possible to prevent the degeneration of motor neurons, thereby halting the progression of the disease.
The findings appear in the journal Human Molecular Genetics.