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Book of Abstracts: Albany 2011

category image Albany 2011
Conversation 17
June 14-18 2011
©Adenine Press (2010)

Structure, Function and Evolutionary Relationship of the Leptin Receptor (OB – Rb)

In view of the release of more and more genome sequences, the genome sequence comparisons and phylogenetic tree constructions have become popular (1-3) and it will be useful to use this methodology to understand body weight regulation and energy homeostasis. Leptin, a 16 kDa adipocytic protein hormone is known to play a central role in regulation of body weight and energy homeostasis; it is known to regulate various physiological functions such as reproduction, hematopoiesis, inflammation etc. (4, 5). Leptin acts via its specific receptor (OB – R) or LR. and till date six splice variants of OB – R have been identified and mapped to the db gene locus on chromosome 1p in human. Of the six, the longest isoform OB – Rb which is highly expressed in hypothalamus has the signaling capability and the structure-functional relationship of this has been analysed in detail.

Alignment of the aminoacid sequences of leptin receptor (OB-Rb) from different species such as human, mouse, pig, cattle, bat, turkey, frog, zebra and madaka fish OB- Rb reveals that most of the regions including the N – terminal, transmembrane (TM), disulphide bridges and C – terminal regions are highly conserved in mammalian species with subtle variations is madaka and zebra fish. Phylogenetic analysis is suggestive of evolutionary relationship between human, monkey, cattle etc., pig and sheep, rat and mouse, zebra fish and madaka fish with distinct variation in elelephant, details of which will be discussed.

References

  1. V. Sabbia, H. Romero, H. Musto and H. Naya, J Biomol Struct Dyn 27, 361-369 (2009).
  2. P. Anbazhagan, M. Purushottam, H. B. K. Kumar, O. Mukherjee, S. Jain, and R. Sowdhamini, J Biomol Struct Dyn 27, 581-598 (2010).
  3. Z. Liu, Y. Xu, L. Wu, and S. Zhang, J Biomol Struct Dyn 28, 97-106 (2010).
  4. Y. Zhang, R. Proenca, M. Maffei, M. Barone, L. Leopold and J. M. Friedman, Nature 372, 425-432 (1994).
  5. A. A. Steiner, A. A. Romanovsky, Prog Lipid Res. 46, 89-107 (2007).


R. Malathi*
R. Raskin Erusan

Department of Genetics
Dr. A.L.M. Post Graduate Institute of Basic Medical Sciences
University of Madras
Chennai- 600 113. India.

ph: 91 – 044 -24547062
fx: 91- 044 – 24540709
Email: r_malathi@hotmail.com