nicotinamide riboside kinase 2; NRK 2; NmR-K 2; integrin beta-1-binding protein 3; muscle integrin-binding protein; MIBP; nicotinic acid riboside kinase 2; ribosylnicotinamide kinase 2; RNK 2; ribosylnicotinic acid kinase 2 (ITGB1BP3, NRK2, NMRK2)

Function

• cofactor biosynthesis; NAD+ biosynthesis
• attenuates laminin matrix deposition & cell adhesion to laminin, but not to fibronectin
• regulation of PXN & PXN tyrosine phosphorylation
• regulation of terminal myogenesis
• catalyzes synthesis of nicotinamide nucleotide from nicotinamide riboside
• Preiss-Handler independent NAD biosynthesis.
• interacts with ITGB1

ATP + N-ribosylnicotinamide = ADP + nicotinamide ribonucleotide

Kinetic parameters:

• KM=0.19 mM for nicotinamide riboside (with ATP as cosubstrate)
• KM=30 mM for nicotinamide riboside (with GTP as cosubstrate)
• KM=0.11 mM for tiazofurin (with ATP as cosubstrate)
• KM=0.063 mM for nicotinic acid riboside (with ATP as cosubstrate)
• KM=1.3 mM for uridine (with ATP as cosubstrate)

Structure

• monomer (putative)
• belongs to the uridine kinase family, NRK subfamily

Alternative splicing

named isoforms=2

Expression

• expressed predominantly in skeletal muscle
• expressed at a lower level in heart (at protein level)
• not expressed in brain, kidney, liver, lung, pancreas or placenta
• down-regulated during myoblast differentiation

More general terms

• kinase or ATP-phosphotransferase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=27231
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:27231
• OMIM: https://mirror.omim.org/entry/608705
• UniProt: http://www.uniprot.org/uniprot/Q9NPI5.html