We have investigated the structure of the small nuclear RNP (snRNP) U1 by combining EM of complete and partially protein-deficient particles with immunoelectron microscopy employing mAbs against known components of the U1 snRNP. It was found that the two main protuberances of this particle can be identified with the U1-specific proteins A and 70K. The 70K protuberance is the one lying closer to the 5' terminus of the snRNA, as identified by its 5'-terminal m3G cap. The round-shaped main body of U1 snRNP represents its core RNP domain containing the common snRNP proteins. Functional implications of these results are discussed. Our results may also point to the physical basis for the production of autoantibodies directed against specific groups of snRNP proteins. The physical grouping of the common proteins (Sm epitopes) and the specific proteins (RNP epitopes) could result in one or the other being presented to the immune system as is the case in patients suffering from SLE or MCTD, respectively.
Skip Nav Destination
Article navigation
15 February 1992
Article|
February 15 1992
Structure of the small nuclear RNP particle U1: identification of the two structural protuberances with RNP-antigens A and 70K.
B Kastner,
B Kastner
Institut für Molekularbiologie und Tumorforschung, Marburg, Germany.
Search for other works by this author on:
U Kornstädt,
U Kornstädt
Institut für Molekularbiologie und Tumorforschung, Marburg, Germany.
Search for other works by this author on:
M Bach,
M Bach
Institut für Molekularbiologie und Tumorforschung, Marburg, Germany.
Search for other works by this author on:
R Lührmann
R Lührmann
Institut für Molekularbiologie und Tumorforschung, Marburg, Germany.
Search for other works by this author on:
B Kastner
Institut für Molekularbiologie und Tumorforschung, Marburg, Germany.
U Kornstädt
Institut für Molekularbiologie und Tumorforschung, Marburg, Germany.
M Bach
Institut für Molekularbiologie und Tumorforschung, Marburg, Germany.
R Lührmann
Institut für Molekularbiologie und Tumorforschung, Marburg, Germany.
Online ISSN: 1540-8140
Print ISSN: 0021-9525
J Cell Biol (1992) 116 (4): 839–849.
Citation
B Kastner, U Kornstädt, M Bach, R Lührmann; Structure of the small nuclear RNP particle U1: identification of the two structural protuberances with RNP-antigens A and 70K.. J Cell Biol 15 February 1992; 116 (4): 839–849. doi: https://doi.org/10.1083/jcb.116.4.839
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionEmail alerts
Advertisement
Advertisement