Sequence of the human glycogen-associated regulatory subunit of type 1 protein phosphatase and analysis of its coding region and mRNA level in muscle from patients with NIDDM

TY - JOUR

T1 - Sequence of the human glycogen-associated regulatory subunit of type 1 protein phosphatase and analysis of its coding region and mRNA level in muscle from patients with NIDDM

AU - Chen, Y H

AU - Hansen, L

AU - Chen, Min

AU - Bjørbaek, C

AU - Vestergaard, H

AU - Hansen, T

AU - Cohen, Peter

AU - Pedersen, O

AU - Vestergaard, Henrik

PY - 1994/10

Y1 - 1994/10

N2 - Impaired insulin-stimulated glycogen synthesis of peripheral tissues is a characteristic feature of many patients with non-insulin-dependent diabetes mellitus (NIDDM) and their first-degree relatives with normal glucose tolerance, suggesting putative inherited defects in this metabolic pathway. In previous studies, we have failed to reveal mutations in the coding regions of the muscle-specific glycogen synthase gene and the three genes that encode the catalytic subunits of protein phosphatase 1 (PP1) as frequent causes of insulin resistance. Because the glycogen-associated regulatory subunit of protein phosphatase 1 (PP1 G-subunit) plays a key role in the insulin stimulation of glycogen synthesis and the activity of PP1 is decreased in insulin-resistant subjects, we have now cloned the human G-subunit cDNA to search for abnormalities in the corresponding gene (designated PPP1R3 in the human genome nomenclature) in patients with NIDDM. The human cDNA was isolated from a skeletal muscle cDNA library and was found to encode a 126-kDa protein, which shows 73% amino acid identity to the rabbit PP1 G-subunit. The human G-subunit cDNA from 30 insulin-resistant NIDDM patients was analyzed for genetic variations in the G-subunit by using single-stranded conformation polymorphism (SSCP) scanning of reversely transcribed mRNA. One variant SSCP profile was detected in the region encoding the COOH-terminal part of the PP1 G-subunit in only one NIDDM patient, and subsequent nucleotide sequencing showed a C to A transversion on one allele at base position 2792. This change predicts an amino acid substitution from alanine to glutamic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

AB - Impaired insulin-stimulated glycogen synthesis of peripheral tissues is a characteristic feature of many patients with non-insulin-dependent diabetes mellitus (NIDDM) and their first-degree relatives with normal glucose tolerance, suggesting putative inherited defects in this metabolic pathway. In previous studies, we have failed to reveal mutations in the coding regions of the muscle-specific glycogen synthase gene and the three genes that encode the catalytic subunits of protein phosphatase 1 (PP1) as frequent causes of insulin resistance. Because the glycogen-associated regulatory subunit of protein phosphatase 1 (PP1 G-subunit) plays a key role in the insulin stimulation of glycogen synthesis and the activity of PP1 is decreased in insulin-resistant subjects, we have now cloned the human G-subunit cDNA to search for abnormalities in the corresponding gene (designated PPP1R3 in the human genome nomenclature) in patients with NIDDM. The human cDNA was isolated from a skeletal muscle cDNA library and was found to encode a 126-kDa protein, which shows 73% amino acid identity to the rabbit PP1 G-subunit. The human G-subunit cDNA from 30 insulin-resistant NIDDM patients was analyzed for genetic variations in the G-subunit by using single-stranded conformation polymorphism (SSCP) scanning of reversely transcribed mRNA. One variant SSCP profile was detected in the region encoding the COOH-terminal part of the PP1 G-subunit in only one NIDDM patient, and subsequent nucleotide sequencing showed a C to A transversion on one allele at base position 2792. This change predicts an amino acid substitution from alanine to glutamic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

KW - Amino Acid Sequence

KW - Animals

KW - Base Sequence

KW - DNA Primers

KW - Diabetes Mellitus, Type 2

KW - Female

KW - Glucose

KW - Glycogen

KW - Humans

KW - Macromolecular Substances

KW - Male

KW - Middle Aged

KW - Molecular Sequence Data

KW - Muscles

KW - Phosphoprotein Phosphatases

KW - Polymerase Chain Reaction

KW - Polymorphism, Genetic

KW - Protein Phosphatase 1

KW - RNA, Messenger

KW - Rabbits

KW - Reference Values

KW - Sequence Homology, Amino Acid

M3 - Journal article

C2 - 7926294

SN - 0012-1797

VL - 43

SP - 1234

EP - 1241

JO - Diabetes

JF - Diabetes

IS - 10

ER -