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Characterization of LPTM4B: A Computational Approach

By: Zaira Rehman, Hajra Sadia, Ammad Fahim

Key Words: Lysosomal-associated protein transmembrane-4 beta, Extra cellular domain, Multi drug resistance

Int. J. Biosci. 10(4), 295-301, April 2017.



Lysosomal-associated protein transmembrane-4 beta (LAPTM4B) is a putative novel oncogene. Elevated expression has been observed in many solid tumors as HCC, lung, breast, colon and ovarian cancer. The expression of LAPTM4B is also associated with MDR1 expression in solid tumors. Despite the importance of LAPTM4B in cancer progression and chemotherapy resistance, the structure of LAPTM4B is not known. The current study aimed to identify the three dimensional structure of LAPTM4B and its interactions with MDR1. Protscale server was used to predict the hydrophilicity, accessibility, polarity, flexibility, mutability, bulkiness and refractivity of LAPTM4B and results showed that it is a stable protein. There is no signal peptide in LAPTM4B as predicted through Signal Server. One acetylation site present in LAPTM4B at Ser3 as predicted through Net Acet. One O-linked glycosylation site present at position 62. According to Netphos 3.1 server predictions ten threonine phosphorylation sites, fourteen serine phosphorylation sites, four tyrosine specific phosphorylation sites might present in LAPTM4B. PKC and PKA are kinases do phosphorylation of LAPTM4B. Different physiological parameter of LAPTM4B was predicted trough Protparam server. Secondary structure showed that LAPTM4B is structured protein with alpha helices, coils and one beta sheet. Due to absence of any structural template, ab-initio modeling was used to predict three dimensional structure of LAPTM4B. The structure was stable and it may accord with the rule of stereochemistry. LAPTM4B was predicted to interact with ABCB1, PIK3R1 and so on. These results will help to understand protein structure and how it involved in multidrug resistance.

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Characterization of LPTM4B: A Computational Approach

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Zaira Rehman, Hajra Sadia, Ammad Fahim. 2017. Characterization of LPTM4B: A Computational Approach. Int. J. Biosci. 10(4), 295-301.
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