Morales-Garcia 2016 Abstract MitoFit Science Camp 2016

From Bioblast
Respiratory deficiencies in isolated mitochondria from a Ξ”-shy1 S. cerevisiae strain.


Lilia Morales-Garcia

Morales-Garcia L, Cruz-Cruz I, Uribe-Alvarez C, Chiquete-Felix N, Uribe-Carvajal S (2016)

Event: MitoFit Science Camp 2016 Kuehtai AT

Leigh syndrome is a hereditary disease characterized by progressive neurological degeneration. The underlying cause of the disease is defective oxidative phosphorylation. Leigh syndrome may result from defects in different respiratory complexes. One such case is the disfunction of chaperonin SURF1, which catalyzes incorporation of subunit I into Complex IV. This defect results in deficient cytochrome oxidase activity and most likely leads to the clinical manifestations. In yeast, the orthologue of SURF1 is SHY1 [1,2]. SHY1 possesses two transmembrane domains and remains in the inner mitochondrial membrane, even after it has fulfilled its assembly role. Thus, it would be of interest to determine whether SHY1 has other functions besides being a chaperonin.

We examined mitochondrial function in a βˆ†Shy1 Saccharomyces cerevisiae mutant strain grown in YPGal for 24 h at 30ΒΊC. Cells were disrupted using a Bead-beater (Biospec Product Inc., USA) and 0.5 mm diameter glass beads.[3] From the homogenate, mitochondria were isolated by differential centrifugation. Protein concentration was determined by biuret.

The rate of oxygen consumption was measured in an oxymeter, the resting state and in the phosphorylating state; transmembrane potential was determined using safranine-O, following the absorbance changes at 511-533nm in a DW2000 Aminco/Olis spectrophotometer in dual mode[4] and mitochondrial swelling was measured at 540 nm in the same spectrophotometer in split mode. The concentrations of Pi were 0.1, 0.4,1, 2 and 4 mM.

As expected, the respiratory chain was highly inhibited as a result of a defective complex IV activity. No other functions, such as the permeability transition seemed to be affected. It is still necessary to keep studying SHY1 to determine whether it has additional functions.

β€’ O2k-Network Lab: MX Mexico City Uribe-Carvajal S

Labels: MiParea: Respiration, mt-Medicine  Pathology: Neurodegenerative 

Organism: Saccharomyces cerevisiae 

Enzyme: Complex IV;cytochrome c oxidase 

HRR: Oxygraph-2k  Event: B2  MitoFit Science Camp 2016, Safranine-O 


1-Inst Fisiol Celular, UNAM, Mexico. - [email protected]


  1. Barrientos A, Tzagoloff A (2004) Mss51p and Cox 14p jointly regalarte mitochondial Cox1p expresiΓ³n in Saccharomyces cerevisiae. EMBO J 23:3472-82.
  2. Perez-Martinez X, Butler CA, Shingu-Vazquez M, Fox TD (2009) Dual functions of Mss51 couple synthesis of Cox1 to assembly of cytochrome c oxidase in Saccharomyces cerevisiae mitochondria. Mol Biol Cell 20:4371-80.
  3. Uribe S, Ramirez J, Pena A (1985) Effects of beta-pinene on yeast membrane functions. J Bacteriol 161:1195–1200.
  4. Akerman KE, WikstrΓΆm MK (1976) Safranine as a probe of the mitochondrial membrane potential. FEBS Lett 68:191–7.
Cookies help us deliver our services. By using our services, you agree to our use of cookies.