Creatine (Cr) is an important high-energy phosphate buffer in tissues with a high energy demand such as muscle and brain and is consequently a highly consumed nutritional supplement. Creatine is synthesized via the S-adenosylmethionine (SAM) dependent methylation of guanidinoacetate (GAA) which is not regulated by a feedback mechanism. The first objective of this study was to determine the effe...

Pompe disease is a form of muscular dystrophy due to lysosomal storage of glycogen caused by deficiency of acid α-glucosidase (GAA). Respiratory failure in Pompe disease has been attributed to respiratory muscle dysfunction. However, evaluation of spinal tissue from Pompe patients and animal models indicates glycogen accumulation and lower motoneuron pathology. We hypothesized that restoring GA...

Friedreich ataxia is a degenerative disease caused by deficiency of the protein frataxin (FXN). An intronic expansion of GAA triplets in the FXN-encoding gene, FXN, causes gene silencing and thus reduced FXN protein levels. Although it is widely assumed that GAA repeats block transcription via the assembly of an inaccessible chromatin structure marked by methylated H3K9, direct proof for this i...

Guanidinoacetic acid (GAA) is the biosynthetic precursor of creatine which is involved in storage and transmission of phosphate-bound energy. Hepatocytes readily convert GAA to creatine, raising the possibility that the active uptake of GAA by hepatocytes is a regulatory factor. The purpose of this study is to investigate and identify the transporter responsible for GAA uptake by hepatocytes. T...

The effects of dietary supplemental guanidinoacetic acid (GAA) on performance, biochemical indices and meat pH of broilers with cold-induced ascites were studied. A total of 640 day-old male broiler chicks (Cobb 500) were assigned to four dietary treatments including control diet; control diet supplemented with either 0.6, 1.2 or 1.8 g of GAA per kg of feed. Each treatment was replicated in 8 b...

It is reported that gossypol acetate (GAA) has obvious effects on inhibiting the growth of tumors, by inhibiting the activity of enzymes. Ultrastructural study showed that GAA can cause morphological changes of mitochondria which leads to the apoptosis of tumors. However, little is known about the pathways that how the GAA triggers apoptosis of tumors and what kind of the molecular events have ...

BACKGROUND Friedreich's ataxia, the most common inherited ataxia, is associated with a mutation that consists of an unstable expansion of GAA repeats in the first intron of the frataxin gene on chromosome 9, which encodes a protein of unknown function. METHODS We studied 187 patients with autosomal recessive ataxia, determined the size of the GAA expansions, and analyzed the clinical manifest...

Ganoderma lucidum is a medicinal fungus whose numerous triterpenoids are its main bioactive constituents. Although hundreds of have been identified, triterpenoid glycosides, also named saponins, rarely found. Ganoderic acid A (GAA), major triterpenoid, was synthetically cascaded to form GAA-15-O-?-glucopyranoside (GAA-15-G) by glycosyltransferase (BtGT_16345) from Bacillus thuringiensis GA A07 ...

Friedreich's ataxia is an incurable genetic disorder caused by a mutant expansion of the trinucleotide GAA within an intronic FXN RNA. This expansion leads to reduced expression of frataxin (FXN) protein and evidence suggests that transcriptional repression is caused by an R-loop that forms between the expanded repeat RNA and complementary genomic DNA. Synthetic agents that increase levels of F...