Khaled Machaca, PhD

Khaled Machaca, PhD

Professor of Physiology and Biophysics
Associate Dean for Research

 (+974) 4492 8423


Emory University, Atlanta, GA 1996

Postdoctoral Fellow
Emory University, 1996-1999



Dr. Machaca is an internationally renowned researcher in the fields of Ca2+ signaling and gamete maturation. He has published multiple high impact scientific articles in leading journals and garnered continuous extramural research funding from federal and National funding agencies, including the National Institutes of Health (USA) and the Qatar National Research Fund (QNRF). Research efforts in the Machaca Lab presently focus on the regulation of Ca2+ signaling pathways in both physiological and pathological conditions. Specific projects include Ca2+ signaling during oocyte maturation in preparation for egg-to-embryo transition, the regulation of the meiotic cell cycle, Ca2+ signaling in vascular smooth muscle cells in hypertension, the mechanisms underlying store operated Ca2+ entry and the regulation of IP3-dependent Ca2+ release during meiosis.

Dr. Machaca is presently Professor of Physiology and Biophysics and serves as Associate Dean for Research. In that role he oversees the operational, academic and financial management of the research enterprise at Weill Cornell Medicine - Qatar.

Selected Publications

  • Yu F, Sun L, and Machaca K. Orai1 internalization and STIM1 clustering inhibition modulate SOCE inactivation during meiosis. Proceedings of the National Academy of Sciences 2009;106:17401-6.
  • Yu F, Sun L, and Machaca K. Constitutive recycling of the store-operated Ca2+ channel Orai1, and its internalization during meiosis. J Cell Biology 2010 Nov 1; 191(3)523-35
  • Yu F, Sun L, Courjaret R, and Machaca K. Role of the STIM1 C-terminal domain in STIM1 clustering. Journal of Biological Chemistry 2011 Mar 11; 286(10):8375-84.
  • Courjaret R, and Machaca K. STIM1 and Orai1 in cellular proliferation and division. Front Biosci (Elite Ed). 2012 Jan 1;4:331-41.
  • Sun L, Yu F, Ullah A, Hubrack S, Daalis A, Jung P, and Machaca K. Endoplasmic reticulum remodeling tunes IP3-dependent Ca2+ release sensitivity. PLoS One. 2011; 6:e27928.
  • Lee B, Palermo G, and Machaca K. Down-regulation of store-operated Ca2+ entry during mammalian meiosis is required for the egg-to-embryo transition. Journal of Cell Science. 2013; In Press.
  • Yu F, Sun L, Hubrack S, Selvaraj S, Machaca K. Intramolecular shielding maintains STIM1 in an inactive conformation. Journal of Cell Science 2013; In Press.