Structural aspects of the interaction of the cytoplasmic domain of Mucin-1 (MUC1) with the SH3 domain of Src Kinase

• Author / Creator

  Marasinghe Arachchige, Bodhi Nirosha

• Abstract
  Breast cancer is the second most frequent cause of cancer deaths in Canadian women with death resulting from the spread of cancer cells or metastasis to distal organs. Our laboratory was the first to show that MUC1, a type-1 transmembrane glycoprotein highly overexpressed in breast tumors, may contribute to migration of breast cancer cells by binding to the Intercellular adhesion molecule-1 (ICAM-1), which triggers the recruitment of non-receptor tyrosine kinase, Src that initiates the downstream signaling. However, the structural aspects of the interaction of cytoplasmic domain of MUC1 (MUC1-CD) and the Src-SH3 domain are still unknown. This thesis, aims to determine the affinity and specificity of this interaction using multinuclear, multidimensional nuclear magnetic resonance (NMR) spectroscopy/titration studies using 15N labeled Src-SH3 domain and the synthetic peptides of MUC1-CD. The results revealed that the dissociation constant (KD) for the interaction of 69-residue full-length MUC1-CD and Src-SH3 domain is 1.85 mM, based on the residues that show the highest chemical shift changes (> 0.04 ppm). Although the residue-shifts were very small (< 0.1 ppm) different-length MUC1-peptides produced the same results. The most perturbed residues were, Arg98, Glu100, Leu103, His125, Thr132 and Gly130 located outside the canonical binding site, suggesting that MUC1-CD binds with a high specificity but a low affinity to a non-canonical site. The results form a foundation for further structural studies exploring the molecular recognition mechanisms of the MUC1/Src-SH3 interaction.

• Subjects / Keywords

  • Src Kinase
  • SH3 domain
  • NMR
  • MUC1

• Graduation date

  Fall 2011

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3F667

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.