Molecular physiology of the SERCA and SPCA pumps.
Intracellular Ca(2+)-transport ATPases exert a pivotal role in the endoplasmic reticulum and in the compartments of the cellular secretory pathway by maintaining a sufficiently high lumenal Ca(2+) (and Mn(2+)) concentration in these compartments required for an impressive number of vastly different cell functions. At the same time this lumenal Ca(2+) represents a store of releasable activator Ca(2+) controlling an equally impressive number of cytosolic functions. This review mainly focuses on the different Ca(2+)-transport ATPases found in the intracellular compartments of mainly animal non-muscle cells: the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) pumps. Although it is not our intention to treat the ATPases of the specialized sarcoplasmic reticulum in depth, we can hardly ignore the SERCA1 pump of fast-twitch skeletal muscle since its structure and function is by far the best understood and it can serve as a guide to understand the other members of the family. In a second part of this review we describe the relatively novel family of secretory pathway Ca(2+)/Mn(2+) ATPases (SPCA), which in eukaryotic cells are primarily found in the Golgi compartment.
Wuytack
F
F
Laboratorium voor Fysiologie, K.U.Leuven, Campus Gasthuisberg, Leuven, Belgium. frank.wuylack@med.kuleuven.ac.be
Raeymaekers
L
L
Missiaen
L
L
D000595:Amino Acid Sequence; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000737:chemistry* / Q000502:physiology*; D000252:Calcium-Transporting ATPases / Q000737:chemistry* / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D017386:Sequence Homology, Amino Acid
D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases