Received: 11 February 2018 | Accepted: 24 May 2018 DOI: 10.1002/jcb.27186 RESEARCH ARTICLE Leishmania donovani infection differentially regulates small G‐proteins Atahar Husein 1 | Azfar Jamal 2 | Mohammad Zulfazal Ahmed 1 | Mohammad Arish 1 | Rahat Ali 1 | Shams Tabrez 1 | Fayyaz Rasool 1 | Abdur Rub 1,3 1 Infection and Immunity Lab (Lab No. 414), Department of Biotechnology, Jamia Millia Islamia, New Delhi, India 2 Virology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India 3 Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah, Saudi Arabia Correspondence Abdur Rub, Infection and Immunity Lab (Lab No. 414), Department of Biotechnology, Jamia Millia Islamia, Jamia Nagar, New Delhi-110025, India. Email: arub@jmi.ac.in; a.ahmad@mu. edu.sa; abdurrub81@gmail.com Funding information Indian Council of Medical Research (ICMR); UGC; SERB; INSA; AYUSH, Grant/Award Number: Z.28015/252/2015‐ HPC (EMR)‐AYUSH‐C Abstract Leishmania is a protozoan parasite that resides and replicates in macrophages and causes leishmaniasis. The parasite alters the signaling cascade in host macrophages and evades the host machinery. Small G‐proteins are GTPases, grouped in 5 different families that play a crucial role in the regulation of cell proliferation, cell survival, apoptosis, intracellular trafficking, and transport. In particular, the Ras family of small G‐proteins has been identified to play a significant role in the cellular functions mentioned before. Here, we studied the differential expression of the most important small G‐proteins during Leishmania infection. We found major changes in the expression of different isoforms of Ras, mainly in N‐Ras. We observed that Leishmania donovani infection led to enhanced N‐Ras expression, whereas it inhibited K‐Ras and H‐Ras expression. Furthermore, an active N‐Ras pull‐down assay showed enhanced N‐Ras activity. L donovani infection also increased extracellular signal–regulated kinase 1/2 phosphorylation and simultaneously decreased p38 phosphorylation. In contrast, pharmacological inhibition of Ras led to reduction in the phosphorylation of extracellular signal–regulated kinase 1/2 and enhanced the phosphorylation of p38 in Leishmania‐infected cells, which could lead to increased interleukin‐12 expression and decreased interleukin‐10 expression. Indeed, farnesylthiosalicyclic acid (a Ras inhibitor), when used at the effective level in L donovani–infected macrophages, reduced amastigotes in the host macrophages. Thus, upregulated N‐Ras expression during L donovani infection could be a novel immune evasion strategy of Leishmania and would be a potential target for antileishmanial immunotherapy. KEYWORDS extracellular signal–regulated kinase (ERK1/2), Leishmania, macrophages, p38, Ras, signaling 1 | INTRODUCTION Leishmania is a protozoan parasite that causes leishma- niasis. It is found in 89 different countries across the world. 1-3 Leishmaniasis is spread worldwide, with 1.5‐2.0 million new cases reported annually, and J Cell Biochem. 2018;1–11. wileyonlinelibrary.com/journal/jcb © 2018 Wiley Periodicals, Inc. | 1 Abbreviations: ERK, extracellular signal–regulated kinase; FTS, farnesylthiosalicyclic acid; HEPES, (4-(2-hydroxyethyl)-1-piperazi- neethanesulfonic acid); IL, interleukin; IP, Immunoprecipitation; MAPK, mitogen‐activated protein kinase; RPMI, Roswell Park Memorial Institute; TBST, tris-buffered saline.