Expression of cytosolic 5' nucleotidase does not correlate with expression of oxidative metabolism marker: myoglobine in human skeletal muscles.

Our previous studies had shown that cytosolic 5'nucleotidase-I (cN-I) is expressed in several tissues in pigeons, including brain and several different skeletal muscles. We observed that cN-I mRNA levels varied among different pigeon muscles. Initial quantification of the differences revealed that about 5-10 times more of cN-I transcript was present in red, oxidative muscles (breast muscle and gastrocnemius) than in white ones, composed of glycolytic fibers (biceps brachii).

Adenosine as a metabolic regulator of tissue function: production of adenosine by cytoplasmic 5'-nucleotidases.

Adenosine is a product of complete dephosphorylation of adenine nucleotides which takes place in various compartments of the cell. This nucleoside is a significant signal molecule engaged in regulation of physiology and modulation of the function of numerous cell types (i.e.

Interaction of nucleoredoxin with protein phosphatase 2A.

A trimeric protein phosphatase 2A (PP2A(T55)) composed of the catalytic (PP2Ac), structural (PR65/A), and regulatory (PR55/B) subunits was isolated from rabbit skeletal muscle by thiophosphorylase affinity chromatography, and contained two additional proteins of 54 and 55 kDa, respectively. The 54 kDa protein was identified as eukaryotic translation termination factor 1 (eRF1) and as a PP2A interacting protein. The 55 kDa protein is now identified as nucleoredoxin (NRX).

Isolation and characterization of pigeon breast muscle cytosolic 5'-nucleotidase-I (cN-I).

5'-Nucleotidase specific towards dCMP and AMP was isolated from avian breast muscle and characterized. It was found to be similar to a type-I form (cN-I) identified earlier as the AMP-selective 5'-nucleotidase responsible for adenosine formation during ATP breakdown in transfected COS-7 cells. Expression pattern of the cN-I gene in pigeon tissues indicated breast muscle as a rich source of the transcript.

Interaction of maize (Zea mays) protein phosphatase 2A with tubulin.

Immunological and biochemical evidence has been obtained for an interaction of maize protein phosphatase 2A (PP2A) holoenzyme with tubulin. Tubulin co-purifies with maize seedling PP2A. Affinity chromatography of the maize PP2A preparation on immobilized tubulin revealed two peaks of phosphorylase alpha phosphatase activity.