Probing the role of proline -135 on the structure, stability, and cell proliferation activity of human acidic fibroblast growth factor.


Abstract

Human acidic fibroblast growth factor 1 (hFGF1) is a protein intricately involved in cell growth and tissue repair. In this study, we investigate the effect(s) of understanding the role of a conserved proline (P135), located in the heparin binding pocket, on the structure, stability, heparin binding affinity, and cell proliferation activity of hFGF1. Substitution of proline-135 with a positively charged lysine (P135K) resulted in partial destabilization of the protein; however, the overall structural integrity of the protein was maintained upon substitution of proline-135 with either a negative charge (P135E) or a polar amino acid (P135Q). Interestingly, upon heparin binding, an increase in thermal stability equivalent to that of wt-hFGF1 was observed when P135 was replaced with a positive (P135K) or a negative charge (P135E), or with a polar amino acid (P135Q). Surprisingly, introduction of negative charge in the heparin-binding pocket at position 135 (P135E) increased hFGF1's affinity for heparin by 3-fold, while the P135K mutation, did not alter the heparin-binding affinity. However, the enhanced heparin-binding affinity of mutant P135E did not translate to an increase in cell proliferation activity. Interestingly, the P135K and P135E double mutations, P135K/R136E and P135/R136E, reduced the heparin binding affinity by ∼3-fold. Furthermore, the cell proliferation activity was increased when the charge reversal mutation R136E was paired with both P135E (P135E/R136E) and P135K (P135K/R136E). Overall, the results of this study suggest that while heparin is useful for stabilizing hFGF1 on the cell surface, this interaction is not mandatory for activation of the FGF receptor.

Submission Details

ID: SgQVErXY

Submitter: Connie Wang

Submission Date: Sept. 28, 2018, 4:24 p.m.

Version: 1

Publication Details
Davis JE;Alghanmi A;Gundampati RK;Jayanthi S;Fields E;Armstrong M;Weidling V;Shah V;Agrawal S;Koppolu BP;Zaharoff DA;Kumar TKS,Arch Biochem Biophys (2018) Probing the role of proline -135 on the structure, stability, and cell proliferation activity of human acidic fibroblast growth factor. PMID:30031837
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant PDB Entries

Structure ID Release Date Resolution Structure Title
2UUS 2007-03-07T00:00:00+0000 2.2 Crystal structure of the rat FGF1-sucrose octasulfate (SOS) complex.
1AFC 1993-07-13T00:00:00+0000 2.7 STRUCTURAL STUDIES OF THE BINDING OF THE ANTI-ULCER DRUG SUCROSE OCTASULFATE TO ACIDIC FIBROBLAST GROWTH FACTOR
2J3P 2006-08-22T00:00:00+0000 1.4 crystal structure of rat FGF1 at 1.4 A
1BAR 1992-09-29T00:00:00+0000 2.7 THREE-DIMENSIONAL STRUCTURES OF ACIDIC AND BASIC FIBROBLAST GROWTH FACTORS
1K5V 2001-10-12T00:00:00+0000 2.1 Human acidic fibroblast growth factor. 141 amino acid form with amino terminal His tag with Asn106 replaced by Gly (N106G).
1K5U 2001-10-12T00:00:00+0000 2.0 Human acidic fibroblast growth factor. 141 amino acid form with amino terminal His tag with His93 replaced by Gly (H93G).
2K8R 2008-09-22T00:00:00+0000 0 Solution structure of human acidic fibroblast growth factor in complex with anti-angiogenic drug inositol hexaphosphate (IP6)
3BA5 2007-11-07T00:00:00+0000 1.75 Crystal structure of D28A mutant of Human acidic fibroblast growth factor
3BA4 2007-11-07T00:00:00+0000 1.8 Crystal structure of L26D mutant of Human acidic fibroblast growth factor
3BA7 2007-11-07T00:00:00+0000 1.6 Crystal structure of L26N/D28A mutant of Human acidic fibroblast growth factor

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
91.5 Fibroblast growth factor 1 Q9N1S8 FGF1_CAPCA
90.3 Fibroblast growth factor 1 P19596 FGF1_CHICK
90.3 Fibroblast growth factor 1 Q7M303 FGF1_SHEEP
92.3 Fibroblast growth factor 1 P03968 FGF1_BOVIN
95.5 Fibroblast growth factor 1 P61149 FGF1_RAT
95.5 Fibroblast growth factor 1 P61148 FGF1_MOUSE
98.0 Fibroblast growth factor 1 P20002 FGF1_PIG
96.8 Fibroblast growth factor 1 P34004 FGF1_MESAU
100.0 Fibroblast growth factor 1 Q5NVQ3 FGF1_PONAB
100.0 Fibroblast growth factor 1 P05230 FGF1_HUMAN