Nicastrin expression in mouse peripheral tissues is not co-ordinated with presenilin and is high in muscle.
Nicastrin was the first binding partner of presenilin (PS) shown to be a critical component of the presenilin/gamma-secretase complex essential in development and differentiation, and in generation of Alzheimer's disease Abeta amyloid peptide. To investigate the function of this glycoprotein, we compared nicastrin and presenilin protein expression in various mouse tissues. Western blot analysis of PS1, PS2 and nicastrin indicates their expression levels are not coordinated. In adult mouse, nicastrin is highly expressed in muscle membranes, whereas presenilin levels are very low. By Blue Native electrophoresis, a PS1 complex of 400 kDa was detected in lung, brain, thymus and heart; nicastrin was also detected as a 400-kDa complex in brain but in muscle it was detected with a complex mobility of 240 and 290 kDa, suggesting association with alternate protein complexes. Immunocytochemistry confirms strong intracellular expression of nicastrin in skeletal muscle and blood vessel smooth muscle. These findings suggest a function for nicastrin in muscle other than participation in the gamma-secretase complex.
Ilaya
Nancy T
NT
Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia.
Evin
Geneviève
G
Masters
Colin L
CL
Culvenor
Janetta G
JG
D053829:Amyloid Precursor Protein Secretases; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015153:Blotting, Western / Q000379:methods; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism; D045744:Cell Line, Tumor; D004622:Embryo, Mammalian; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008168:Lung / Q000378:metabolism; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009132:Muscles / Q000378:metabolism*; D009447:Neuroblastoma; D053764:Presenilin-1; D053766:Presenilin-2; D017434:Protein Structure, Tertiary / Q000502:physiology; D013950:Thymus Gland / Q000378:metabolism
D015703:Antigens, CD; D051907:Lysosomal Membrane Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C508853:PSEN1 protein, human; C508861:PSEN2 protein, human; D053764:Presenilin-1; D053766:Presenilin-2; C413604:nicastrin protein; D053829:Amyloid Precursor Protein Secretases