Muscle reconstitution by muscle satellite cell descendants with stem cell-like properties.

Recent studies have demonstrated that a distinct subpopulation with stem cell-like characteristics in myoblast culture is responsible for new muscle fiber formation after intramuscular transplantation. The identification and isolation of stem-like cells would have significant implications for successful myogenic cell transfer therapy in human muscle disorders. Using a clonal culture system for mouse muscle satellite cells, we have identified two cell types, designated 'round cells' and 'thick cells', in clones derived from single muscle satellite cells that have been taken from either slow or fast muscle.

Yeast Nap1-binding protein Nbp2p is required for mitotic growth at high temperatures and for cell wall integrity.

Nbp2p is a Nap1-binding protein in Saccharomyces cerevisiae identified by its interaction with Nap1 by a two-hybrid system. NBP2 encodes a novel protein consisting of 236 amino acids with a Src homology 3 (SH3) domain. We showed that NBP2 functions to promote mitotic cell growth at high temperatures and cell wall integrity.